At the very heart of the American idea is the notion that, unlike in other places, we can start from nothing and through hard work have everything. That nothing we can imagine is beyond our reach. That we will pull up stakes, go anywhere, do anything to make our dreams come true. But what if that's just a myth? What if the truth is something very different? What if we are…stuck?

I. What does it mean to be an American?

Full disclosure: I'm British. Partial defense: I was born on the Fourth of July. I also have made my home here, because I want my teenage sons to feel more American. What does that mean? I don't just mean waving flags and watching football and drinking bad beer. (Okay, yes, the beer is excellent now; otherwise, it would have been a harder migration.) I'm talking about the essence of Americanism. It is a question on which much ink—and blood—has been spent. But I think it can be answered very simply: To be American is to be free to make something of yourself. An everyday phrase that's used to admire another ("She's really made something of herself") or as a proud boast ("I'm a self-made man!"), it also expresses a theological truth. The most important American-manufactured products are Americans themselves. The spirit of self-creation offers a strong and inspiring contrast with English identity, which is based on social class. In my old country, people are supposed to know their place. British people, still constitutionally subjects of Her Majesty Queen Elizabeth, can say things like "Oh, no, that's not for people like me." Infuriating.

Americans do not know their place in society; they make their place. American social structures and hierarchies are open, fluid, and dynamic. Mobility, not nobility. Or at least that's the theory. Here's President Obama, in his second inaugural address: "We are true to our creed when a little girl born into the bleakest poverty knows that she has the same chance to succeed as anybody else because she is an American; she is free, and she is equal, not just in the eyes of God but also in our own."

Politicians of the left in Europe would lament the existence of bleak poverty. Obama instead attacks the idea that a child born to poor parents will inherit their status. "The same chance to succeed as anybody else because she is an American…."

Americanism is a unique and powerful cocktail, blending radical egalitarianism (born equal) with fierce individualism (it's up to you): equal parts Thomas Paine and Horatio Alger. Egalitarian individualism is in America's DNA. In his original draft of the Declaration of Independence, Thomas Jefferson wrote that "men are created equal and independent," a sentiment that remained even though the last two words were ultimately cut. It was a declaration not only of national independence but also of a nation of independents.

The problem lately is not the American Dream in the abstract. It is the growing failure to realize it. Two necessary ingredients of Americanism—meritocracy and momentum—are now sorely lacking.

America is stuck.

Almost everywhere you look—at class structures, Congress, the economy, race gaps, residential mobility, even the roads—progress is slowing. Gridlock has already become a useful term for political inactivity in Washington, D. C. But it goes much deeper than that. American society itself has become stuck, with weak circulation and mobility across class lines. The economy has lost its postwar dynamism. Racial gaps, illuminated by the burning of churches and urban unrest, stubbornly persist.

In a nation where progress was once unquestioned, stasis threatens. Many Americans I talk to sense that things just aren't moving the way they once were. They are right. Right now this prevailing feeling of stuckness, of limited possibilities and uncertain futures, is fueling a growing contempt for institutions, from the banks and Congress to the media and big business, and a wave of antipolitics on both left and right. It is an impotent anger that has yet to take coherent shape. But even if the American people don't know what to do about it, they know that something is profoundly wrong.

II. How stuck are we?

Let's start with the most important symptom: a lack of social mobility. For all the boasts of meritocracy—only in America!—Americans born at the bottom of the ladder are in fact now less likely to rise to the top than those situated similarly in most other nations, and only half as likely as their Canadian counterparts. The proportion of children born on the bottom rung of the ladder who rise to the top as adults in the U.S. is 7.5 percent—lower than in the U.K. (9 percent), Denmark (11.7), and Canada (13.5). Horatio Alger has a funny Canadian accent now.

It is not just poverty that is inherited. Affluent Americans are solidifying their own status and passing it on to their children more than the affluent in other nations and more than they did in the past. Boys born in 1948 to a high-earning father (in the top quarter of wage distribution) had a 33 percent chance of becoming a top earner themselves; for those born in 1980, the chance of staying at the top rose sharply to 44 percent, according to calculations by Manhattan Institute economist Scott Winship. The sons of fathers with really high earnings—in the top 5 percent—are much less likely to tumble down the ladder in the U. S. than in Canada (44 percent versus 59 percent). A "glass floor" prevents even the least talented offspring of the affluent from falling. There is a blockage in the circulation of the American elite as well, a system-wide hardening of the arteries.

Exhibit A in the case against the American political elites: the U. S. tax code. To call it Byzantine is an insult to medieval Roman administrative prowess. There is one good reason for this complexity: The American tax system is a major instrument of social policy, especially in terms of tax credits to lower-income families, health-care subsidies, incentives for retirement savings, and so on. But there are plenty of bad reasons, too—above all, the billions of dollars' worth of breaks and exceptions resulting from lobbying efforts by the very people the tax system favors.

So fragile is the American political ego that we can't go five minutes without congratulating ourselves on the greatness of our system, yet policy choices exacerbate stuckness.

The American system is also a weak reed when it comes to redistribution. You will have read and heard many times that the United States is one of the most unequal nations in the world. That is true, but only after the impact of taxes and benefits is taken into account. What economists call "market inequality," which exists before any government intervention at all, is much lower—in fact it's about the same as in Germany and France. There is a lot going on under the hood here, but the key point is clear enough: America is unequal because American policy moves less money from rich to poor. Inequality is not fate or an act of nature. Inequality is a choice.

These are facts that should shock America into action. For a nation organized principally around the ideas of opportunity and openness, social stickiness of this order amounts to an existential threat. Although political leaders declare their dedication to openness, the hard issues raised by social inertia are receiving insufficient attention in terms of actual policy solutions. Most American politicians remain cheerleaders for the American Dream, merely offering loud encouragement from the sidelines, as if that were their role. So fragile is the American political ego that we can't go five minutes without congratulating ourselves on the greatness of our system, yet policy choices exacerbate stuckness and ensure decline.

In Britain (where stickiness has historically been an accepted social condition), by contrast, the issues of social mobility and class stickiness have risen to the top of the political and policy agenda. In the previous U.K. government (in which I served as director of strategy to Nick Clegg, the deputy prime minister), we devoted whole Cabinet meetings to the problems of intergenerational mobility and the development of a new national strategy. (One result has been a dramatic expansion in pre-K education and care: Every 3- and 4-year-old will soon be entitled to 30 hours a week for free.) Many of the Cabinet members were schooled at the nation's finest private high schools. A few had hereditary titles. But they pored over data and argued over remedies—posh people worrying over intergenerational income quintiles.

Why is social mobility a hotter topic in the old country? Here is my theory: Brits are acutely aware that they live in a class-divided society. Cues and clues of accent, dress, education, and comportment are constantly calibrated. But this awareness increases political pressure to reduce these divisions. In America, by contrast, the myth of classlessness stands in the way of progress. The everyday folksiness of Americans—which, to be clear, I love—serves as a social camouflage for deep economic inequality. Americans tell themselves and one another that they live in a classless land of open opportunity. But it is starting to ring hollow, isn't it?

III. For black Americans, claims of equal opportunity have, of course, been false from the founding.

They remain false today. The chances of being stuck in poverty are far, far greater for black kids. Half of those born on the bottom rung of the income ladder (the bottom fifth) will stay there as adults. Perhaps even more disturbing, seven out of ten black kids raised in middle-income homes (i.e., the middle fifth) will end up lower down as adults. A boy who grows up in Baltimore will earn 28 percent less simply because he grew up in Baltimore: In other words, this supersedes all other factors. Sixty-six percent of black children live in America's poorest neighborhoods, compared with six percent of white children.

Recent events have shone a light on the black experience in dozens of U. S. cities.

Behind the riots and the rage, the statistics tell a simple, damning story. Progress toward equality for black Americans has essentially halted. The average black family has an income that is 59 percent of the average white family's, down from 65 percent in 2000. In the job market, race gaps are immobile, too. In the 1950s, black Americans were twice as likely to be unemployed as whites. And today? Still twice as likely.

From heeding the call "Go west, young man" to loading up the U-Haul in search of a better job, the instinctive restlessness of America has always matched skills to work, people to opportunities, labor to capital.

Race gaps in wealth are perhaps the most striking of all. The average white household is now thirteen times wealthier than the average black one. This is the widest gap in a quarter of a century. The recession hit families of all races, but it resulted in a wealth wipeout for black families. In 2007, the average black family had a net worth of $19,200, almost entirely in housing stock, typically at the cheap, fragile end of the market. By 2010, this had fallen to $16,600. By 2013—by which point white wealth levels had started to recover—it was down to $11,000. In national economic terms, black wealth is now essentially nonexistent.

Half a century after the passing of the Civil Rights Act, the arc of history is no longer bending toward justice. A few years ago, it was reasonable to hope that changing attitudes, increasing education, and a growing economy would surely, if slowly, bring black America and white America closer together. No longer. America is stuck.

IV. The economy is also getting stuck.

Labor productivity growth, measured as growth in output per hour, has averaged 1.6 percent since 1973. Male earning power is flatlining. In 2014, the median full-time male wage was $50,000, down from $53,000 in 1973 (in the dollar equivalent of 2014). Capital is being hoarded rather than invested in the businesses of the future. U. S. corporations have almost $1.5 trillion sitting on their balance sheets, and many are busily buying up their own stock. But capital expenditure lags, hindering the economic recovery.

New-business creation and entrepreneurial activity are declining, too. As economist Robert Litan has shown, the proportion of "baby businesses" (firms less than a year old) has almost halved since the late 1970s, decreasing from 15 percent to 8 percent—the hallmark of "a steady, secular decline in business dynamism." It is significant that this downward trend set in long before the Great Recession hit. There is less movement between jobs as well, another symptom of declining economic vigor.

Americans are settling behind their desks—and also into their neighborhoods. The proportion of American adults moving house each year has decreased by almost half since the postwar years, to around 12 percent. Long-distance moves across state lines have as well. This is partly due to technological advances, which have weakened the link between location and job prospects, and partly to the growth of economic diversity in cities; there are few "one industry" towns today. But it is also due to a less vibrant housing market, slower rates of new business creation, and a lessening in Americans' appetite for disruption, change, and risk.

This geographic settling is at odds with historic American geographic mobility. From heeding the call "Go west, young man" to loading up the U-Haul in search of a better job, the instinctive restlessness of America has always matched skills to work, people to opportunities, labor to capital. Rather than waiting for help from the government, or for the economic tide to turn back in their favor, millions of Americans changed their life prospects by changing their address. Now they are more likely to stay put and wait. Others, especially black Americans, are unable to escape the poor neighborhoods of their childhood. They are, as the title of an influential book by sociologist Patrick Sharkey puts it, Stuck in Place.

There are everyday symptoms of stuckness, too. Take transport. In 2014, Americans collectively spent almost seven billion hours stuck motionless in traffic—that's a couple days each. The roads get more jammed every year. But money for infrastructure improvements is stuck in a failing road fund, and the railophobia of politicians hampers investment in public transport.

Whose job is it to do something about this? The most visible symptom of our disease is the glue slowly hardening in the machinery of national government. The last two Congresses have been the least productive in history by almost any measure chosen, just when we need them to be the most productive. The U. S. political system, with its strong separation among competing centers of power, relies on a spirit of cross-party compromise and trust in order to work. Good luck there.

V. So what is to be done?

As with anything, the first step is to admit the problem. Americans have to stop convincing themselves they live in a society of opportunity. It is a painful admission, of course, especially for the most successful. The most fervent believers in meritocracy are naturally those who have enjoyed success. It is hard to acknowledge the role of good fortune, including the lottery of birth, when describing your own path to greatness.

There is a general reckoning needed. In the golden years following World War II, the economy grew at 4 percent per annum and wages surged. Wealth accumulated. The federal government, at the zenith of its powers, built interstates and the welfare system, sent GIs to college and men to the moon. But here's the thing: Those days are gone, and they're not coming back. Opportunity and growth will no longer be delivered, almost automatically, by a buoyant and largely unchallenged economy. Now it will take work.

The future success of the American idea must now be intentional.

Entrepreneurial, mobile, aspirational: New Americans are true Americans. We need a lot more of them.

There are plenty of ideas for reform that simply require will and a functioning political system. At the heart of them is the determination to think big again and to vigorously engage in public investment. And we need to put money into future generations like our lives depended on it, because they do: Access to affordable, effective contraception dramatically cuts rates of unplanned pregnancy and gives kids a better start in life. Done well, pre-K education closes learning gaps and prepares children for school. More generous income benefits stabilize homes and help kids. Reading programs for new parents improve literacy levels. Strong school principals attract good teachers and raise standards. College coaches help get nontraditional students to and through college. And so on. We are not lacking ideas. We are lacking a necessary sense of political urgency. We are stuck.

But we can move again if we choose.

In addition to a rejuvenation of policy in all these fields, there are two big shifts required for an American twenty-first-century renaissance: becoming open to more immigration and shifting power from Washington to the cities.

VI. America needs another wave of immigration.

This is in part just basic math: We need more young workers to fund the old age of the baby boomers. But there is more to it than that. Immigrants also provide a shot in the arm to American vitality itself. Always have, always will. Immigrants are now twice as likely to start a new business as native-born Americans. Rates of entrepreneurialism are declining among natives but rising among immigrants.

Immigrant children show extraordinary upward-mobility rates, shooting up the income-distribution ladder like rockets, yet by the third or fourth generation, the rates go down, reflecting indigenous norms. Among children born in Los Angeles to poorly educated Chinese immigrants, for example, an astonishing 70 percent complete a four-year-college degree. As the work of my Brookings colleague William Frey shows, immigrants are migrants within the U. S., too, moving on from traditional immigrant cities—New York, Los Angeles—to other towns and cities in search of a better future. Entrepreneurial, mobile, aspirational: New Americans are true Americans. We need a lot more of them.

This makes a mockery of our contemporary political "debates" about immigration reform, which have become intertwined with race and racism. Some Republicans tap directly into white fears of an America growing steadily browner. More than four in ten white seniors say that a growing population of immigrants is a "change for the worse"; half of white boomers believe immigration is "a threat to traditional American customs and values." But immigration delves deeper into the question of American identity than it does even issues of race. Immigrants generate more dynamism and aspiration, but they are also unsettling and challenging. Where this debate ends will therefore tell us a great deal about the trajectory of the nation. An America that closes its doors will be an America that has chosen to settle rather than grow, that has allowed security to trump dynamism.

VII. The second big shift needed to get America unstuck is a revival of city and state governance.

Since the American Dream is part of the national identity, it seems natural to look to the national government to help make it a reality. But cities are now where the American Dream will live or die. America's hundred biggest metros are home to 67 percent of the nation's population and 75 percent of its economy. Americans love the iconography of the small town, even at the movies—but they watch those movies in big cities.

Powerful mayors in those cities have greater room for maneuvering and making an impact than the average U. S. senator. Even smaller cities and towns can be strongly influenced by their mayor.

There are choices to be made. Class divisions are hardening. Upward mobility has a very weak pulse. Race gaps are widening.

The new federalism in part is being born of necessity. National politics is in ruins, and national institutions are weakened by years of short-termism and partisanship. Power, finding a vacuum in D. C., is diffusive. But it may also be that many of the big domestic-policy challenges will be better answered at a subnational level, because that is where many of the levers of change are to be found: education, family planning, housing, desegregation, job creation, transport, and training. Amid the furor over Common Core and federal standards, it is important to remember that for every hundred dollars spent on education, just nine come from the federal government.

We may be witnessing the end of many decades of national-government dominance in domestic policy-making (the New Deal, Social Security, Medicare, welfare reform, Obamacare). The Affordable Care Act is important in itself, but it may also come to have a place in history as the legislative bookend to a long period of national-policy virtuosity.

The case for the new federalism need not be overstated. There will still be plenty of problems for the national government to fix, including, among the most urgent, infrastructure and nuclear waste. The main tools of macroeconomic policy will remain the Federal Reserve and the federal tax code. But the twentieth-century model of big federal social-policy reforms is in decline. Mayors and governors are starting to notice, and because they don't have the luxury of being stuck, they are forced to be entrepreneurs of a new politics simply to survive.

VIII. It is possible for America to recover its earlier dynamism, but it won't be easy.

The big question for Americans is: Do you really want to? Societies, like people, age. They might also settle down, lose some dynamism, trade a little less openness for a little more security, get a bit stuck in their ways. Many of the settled nations of old Europe have largely come to terms with their middle age. They are wary of immigration but enthusiastic about generous welfare systems and income redistribution. Less dynamism, maybe, but more security in exchange.

America, it seems to me, is not made to be a settled society. Such a notion runs counter to the story we tell ourselves about who we are. (That's right, we. We've all come from somewhere else, haven't we? I just got here a bit more recently.) But over time, our narratives become myths, insulating us from the truth. For we are surely stuck, if not settled. And so America needs to decide one way or the other. There are choices to be made. Class divisions are hardening. Upward mobility has a very weak pulse. Race gaps are widening. The worst of all worlds threatens: a European class structure without European welfare systems to dull the pain.

Americans tell themselves and the world that theirs is a society in which each and all can rise, an inspiring contrast to the hereditary cultures from which it sprang. It's one of the reasons I'm here. But have I arrived to raise my children here just in time to be stuck, too? Or will America be America again?

Editor's note: This piece originally appeared in Esquire.

At the very heart of the American idea is the notion that, unlike in other places, we can start from nothing and through hard work have everything. That nothing we can imagine is beyond our reach. That we will pull up stakes, go anywhere, do anything to make our dreams come true. But what if that's just a myth? What if the truth is something very different? What if we are…stuck?

I. What does it mean to be an American?

Full disclosure: I'm British. Partial defense: I was born on the Fourth of July. I also have made my home here, because I want my teenage sons to feel more American. What does that mean? I don't just mean waving flags and watching football and drinking bad beer. (Okay, yes, the beer is excellent now; otherwise, it would have been a harder migration.) I'm talking about the essence of Americanism. It is a question on which much ink—and blood—has been spent. But I think it can be answered very simply: To be American is to be free to make something of yourself. An everyday phrase that's used to admire another ("She's really made something of herself") or as a proud boast ("I'm a self-made man!"), it also expresses a theological truth. The most important American-manufactured products are Americans themselves. The spirit of self-creation offers a strong and inspiring contrast with English identity, which is based on social class. In my old country, people are supposed to know their place. British people, still constitutionally subjects of Her Majesty Queen Elizabeth, can say things like "Oh, no, that's not for people like me." Infuriating.

Americans do not know their place in society; they make their place. American social structures and hierarchies are open, fluid, and dynamic. Mobility, not nobility. Or at least that's the theory. Here's President Obama, in his second inaugural address: "We are true to our creed when a little girl born into the bleakest poverty knows that she has the same chance to succeed as anybody else because she is an American; she is free, and she is equal, not just in the eyes of God but also in our own."

Politicians of the left in Europe would lament the existence of bleak poverty. Obama instead attacks the idea that a child born to poor parents will inherit their status. "The same chance to succeed as anybody else because she is an American…."

Americanism is a unique and powerful cocktail, blending radical egalitarianism (born equal) with fierce individualism (it's up to you): equal parts Thomas Paine and Horatio Alger. Egalitarian individualism is in America's DNA. In his original draft of the Declaration of Independence, Thomas Jefferson wrote that "men are created equal and independent," a sentiment that remained even though the last two words were ultimately cut. It was a declaration not only of national independence but also of a nation of independents.

The problem lately is not the American Dream in the abstract. It is the growing failure to realize it. Two necessary ingredients of Americanism—meritocracy and momentum—are now sorely lacking.

America is stuck.

Almost everywhere you look—at class structures, Congress, the economy, race gaps, residential mobility, even the roads—progress is slowing. Gridlock has already become a useful term for political inactivity in Washington, D. C. But it goes much deeper than that. American society itself has become stuck, with weak circulation and mobility across class lines. The economy has lost its postwar dynamism. Racial gaps, illuminated by the burning of churches and urban unrest, stubbornly persist.

In a nation where progress was once unquestioned, stasis threatens. Many Americans I talk to sense that things just aren't moving the way they once were. They are right. Right now this prevailing feeling of stuckness, of limited possibilities and uncertain futures, is fueling a growing contempt for institutions, from the banks and Congress to the media and big business, and a wave of antipolitics on both left and right. It is an impotent anger that has yet to take coherent shape. But even if the American people don't know what to do about it, they know that something is profoundly wrong.

II. How stuck are we?

Let's start with the most important symptom: a lack of social mobility. For all the boasts of meritocracy—only in America!—Americans born at the bottom of the ladder are in fact now less likely to rise to the top than those situated similarly in most other nations, and only half as likely as their Canadian counterparts. The proportion of children born on the bottom rung of the ladder who rise to the top as adults in the U.S. is 7.5 percent—lower than in the U.K. (9 percent), Denmark (11.7), and Canada (13.5). Horatio Alger has a funny Canadian accent now.

It is not just poverty that is inherited. Affluent Americans are solidifying their own status and passing it on to their children more than the affluent in other nations and more than they did in the past. Boys born in 1948 to a high-earning father (in the top quarter of wage distribution) had a 33 percent chance of becoming a top earner themselves; for those born in 1980, the chance of staying at the top rose sharply to 44 percent, according to calculations by Manhattan Institute economist Scott Winship. The sons of fathers with really high earnings—in the top 5 percent—are much less likely to tumble down the ladder in the U. S. than in Canada (44 percent versus 59 percent). A "glass floor" prevents even the least talented offspring of the affluent from falling. There is a blockage in the circulation of the American elite as well, a system-wide hardening of the arteries.

Exhibit A in the case against the American political elites: the U. S. tax code. To call it Byzantine is an insult to medieval Roman administrative prowess. There is one good reason for this complexity: The American tax system is a major instrument of social policy, especially in terms of tax credits to lower-income families, health-care subsidies, incentives for retirement savings, and so on. But there are plenty of bad reasons, too—above all, the billions of dollars' worth of breaks and exceptions resulting from lobbying efforts by the very people the tax system favors.

So fragile is the American political ego that we can't go five minutes without congratulating ourselves on the greatness of our system, yet policy choices exacerbate stuckness.

The American system is also a weak reed when it comes to redistribution. You will have read and heard many times that the United States is one of the most unequal nations in the world. That is true, but only after the impact of taxes and benefits is taken into account. What economists call "market inequality," which exists before any government intervention at all, is much lower—in fact it's about the same as in Germany and France. There is a lot going on under the hood here, but the key point is clear enough: America is unequal because American policy moves less money from rich to poor. Inequality is not fate or an act of nature. Inequality is a choice.

These are facts that should shock America into action. For a nation organized principally around the ideas of opportunity and openness, social stickiness of this order amounts to an existential threat. Although political leaders declare their dedication to openness, the hard issues raised by social inertia are receiving insufficient attention in terms of actual policy solutions. Most American politicians remain cheerleaders for the American Dream, merely offering loud encouragement from the sidelines, as if that were their role. So fragile is the American political ego that we can't go five minutes without congratulating ourselves on the greatness of our system, yet policy choices exacerbate stuckness and ensure decline.

In Britain (where stickiness has historically been an accepted social condition), by contrast, the issues of social mobility and class stickiness have risen to the top of the political and policy agenda. In the previous U.K. government (in which I served as director of strategy to Nick Clegg, the deputy prime minister), we devoted whole Cabinet meetings to the problems of intergenerational mobility and the development of a new national strategy. (One result has been a dramatic expansion in pre-K education and care: Every 3- and 4-year-old will soon be entitled to 30 hours a week for free.) Many of the Cabinet members were schooled at the nation's finest private high schools. A few had hereditary titles. But they pored over data and argued over remedies—posh people worrying over intergenerational income quintiles.

Why is social mobility a hotter topic in the old country? Here is my theory: Brits are acutely aware that they live in a class-divided society. Cues and clues of accent, dress, education, and comportment are constantly calibrated. But this awareness increases political pressure to reduce these divisions. In America, by contrast, the myth of classlessness stands in the way of progress. The everyday folksiness of Americans—which, to be clear, I love—serves as a social camouflage for deep economic inequality. Americans tell themselves and one another that they live in a classless land of open opportunity. But it is starting to ring hollow, isn't it?

III. For black Americans, claims of equal opportunity have, of course, been false from the founding.

They remain false today. The chances of being stuck in poverty are far, far greater for black kids. Half of those born on the bottom rung of the income ladder (the bottom fifth) will stay there as adults. Perhaps even more disturbing, seven out of ten black kids raised in middle-income homes (i.e., the middle fifth) will end up lower down as adults. A boy who grows up in Baltimore will earn 28 percent less simply because he grew up in Baltimore: In other words, this supersedes all other factors. Sixty-six percent of black children live in America's poorest neighborhoods, compared with six percent of white children.

Recent events have shone a light on the black experience in dozens of U. S. cities.

Behind the riots and the rage, the statistics tell a simple, damning story. Progress toward equality for black Americans has essentially halted. The average black family has an income that is 59 percent of the average white family's, down from 65 percent in 2000. In the job market, race gaps are immobile, too. In the 1950s, black Americans were twice as likely to be unemployed as whites. And today? Still twice as likely.

From heeding the call "Go west, young man" to loading up the U-Haul in search of a better job, the instinctive restlessness of America has always matched skills to work, people to opportunities, labor to capital.

Race gaps in wealth are perhaps the most striking of all. The average white household is now thirteen times wealthier than the average black one. This is the widest gap in a quarter of a century. The recession hit families of all races, but it resulted in a wealth wipeout for black families. In 2007, the average black family had a net worth of $19,200, almost entirely in housing stock, typically at the cheap, fragile end of the market. By 2010, this had fallen to $16,600. By 2013—by which point white wealth levels had started to recover—it was down to $11,000. In national economic terms, black wealth is now essentially nonexistent.

Half a century after the passing of the Civil Rights Act, the arc of history is no longer bending toward justice. A few years ago, it was reasonable to hope that changing attitudes, increasing education, and a growing economy would surely, if slowly, bring black America and white America closer together. No longer. America is stuck.

IV. The economy is also getting stuck.

Labor productivity growth, measured as growth in output per hour, has averaged 1.6 percent since 1973. Male earning power is flatlining. In 2014, the median full-time male wage was $50,000, down from $53,000 in 1973 (in the dollar equivalent of 2014). Capital is being hoarded rather than invested in the businesses of the future. U. S. corporations have almost $1.5 trillion sitting on their balance sheets, and many are busily buying up their own stock. But capital expenditure lags, hindering the economic recovery.

New-business creation and entrepreneurial activity are declining, too. As economist Robert Litan has shown, the proportion of "baby businesses" (firms less than a year old) has almost halved since the late 1970s, decreasing from 15 percent to 8 percent—the hallmark of "a steady, secular decline in business dynamism." It is significant that this downward trend set in long before the Great Recession hit. There is less movement between jobs as well, another symptom of declining economic vigor.

Americans are settling behind their desks—and also into their neighborhoods. The proportion of American adults moving house each year has decreased by almost half since the postwar years, to around 12 percent. Long-distance moves across state lines have as well. This is partly due to technological advances, which have weakened the link between location and job prospects, and partly to the growth of economic diversity in cities; there are few "one industry" towns today. But it is also due to a less vibrant housing market, slower rates of new business creation, and a lessening in Americans' appetite for disruption, change, and risk.

This geographic settling is at odds with historic American geographic mobility. From heeding the call "Go west, young man" to loading up the U-Haul in search of a better job, the instinctive restlessness of America has always matched skills to work, people to opportunities, labor to capital. Rather than waiting for help from the government, or for the economic tide to turn back in their favor, millions of Americans changed their life prospects by changing their address. Now they are more likely to stay put and wait. Others, especially black Americans, are unable to escape the poor neighborhoods of their childhood. They are, as the title of an influential book by sociologist Patrick Sharkey puts it, Stuck in Place.

There are everyday symptoms of stuckness, too. Take transport. In 2014, Americans collectively spent almost seven billion hours stuck motionless in traffic—that's a couple days each. The roads get more jammed every year. But money for infrastructure improvements is stuck in a failing road fund, and the railophobia of politicians hampers investment in public transport.

Whose job is it to do something about this? The most visible symptom of our disease is the glue slowly hardening in the machinery of national government. The last two Congresses have been the least productive in history by almost any measure chosen, just when we need them to be the most productive. The U. S. political system, with its strong separation among competing centers of power, relies on a spirit of cross-party compromise and trust in order to work. Good luck there.

V. So what is to be done?

As with anything, the first step is to admit the problem. Americans have to stop convincing themselves they live in a society of opportunity. It is a painful admission, of course, especially for the most successful. The most fervent believers in meritocracy are naturally those who have enjoyed success. It is hard to acknowledge the role of good fortune, including the lottery of birth, when describing your own path to greatness.

There is a general reckoning needed. In the golden years following World War II, the economy grew at 4 percent per annum and wages surged. Wealth accumulated. The federal government, at the zenith of its powers, built interstates and the welfare system, sent GIs to college and men to the moon. But here's the thing: Those days are gone, and they're not coming back. Opportunity and growth will no longer be delivered, almost automatically, by a buoyant and largely unchallenged economy. Now it will take work.

The future success of the American idea must now be intentional.

Entrepreneurial, mobile, aspirational: New Americans are true Americans. We need a lot more of them.

There are plenty of ideas for reform that simply require will and a functioning political system. At the heart of them is the determination to think big again and to vigorously engage in public investment. And we need to put money into future generations like our lives depended on it, because they do: Access to affordable, effective contraception dramatically cuts rates of unplanned pregnancy and gives kids a better start in life. Done well, pre-K education closes learning gaps and prepares children for school. More generous income benefits stabilize homes and help kids. Reading programs for new parents improve literacy levels. Strong school principals attract good teachers and raise standards. College coaches help get nontraditional students to and through college. And so on. We are not lacking ideas. We are lacking a necessary sense of political urgency. We are stuck.

But we can move again if we choose.

In addition to a rejuvenation of policy in all these fields, there are two big shifts required for an American twenty-first-century renaissance: becoming open to more immigration and shifting power from Washington to the cities.

VI. America needs another wave of immigration.

This is in part just basic math: We need more young workers to fund the old age of the baby boomers. But there is more to it than that. Immigrants also provide a shot in the arm to American vitality itself. Always have, always will. Immigrants are now twice as likely to start a new business as native-born Americans. Rates of entrepreneurialism are declining among natives but rising among immigrants.

Immigrant children show extraordinary upward-mobility rates, shooting up the income-distribution ladder like rockets, yet by the third or fourth generation, the rates go down, reflecting indigenous norms. Among children born in Los Angeles to poorly educated Chinese immigrants, for example, an astonishing 70 percent complete a four-year-college degree. As the work of my Brookings colleague William Frey shows, immigrants are migrants within the U. S., too, moving on from traditional immigrant cities—New York, Los Angeles—to other towns and cities in search of a better future. Entrepreneurial, mobile, aspirational: New Americans are true Americans. We need a lot more of them.

This makes a mockery of our contemporary political "debates" about immigration reform, which have become intertwined with race and racism. Some Republicans tap directly into white fears of an America growing steadily browner. More than four in ten white seniors say that a growing population of immigrants is a "change for the worse"; half of white boomers believe immigration is "a threat to traditional American customs and values." But immigration delves deeper into the question of American identity than it does even issues of race. Immigrants generate more dynamism and aspiration, but they are also unsettling and challenging. Where this debate ends will therefore tell us a great deal about the trajectory of the nation. An America that closes its doors will be an America that has chosen to settle rather than grow, that has allowed security to trump dynamism.

VII. The second big shift needed to get America unstuck is a revival of city and state governance.

Since the American Dream is part of the national identity, it seems natural to look to the national government to help make it a reality. But cities are now where the American Dream will live or die. America's hundred biggest metros are home to 67 percent of the nation's population and 75 percent of its economy. Americans love the iconography of the small town, even at the movies—but they watch those movies in big cities.

Powerful mayors in those cities have greater room for maneuvering and making an impact than the average U. S. senator. Even smaller cities and towns can be strongly influenced by their mayor.

There are choices to be made. Class divisions are hardening. Upward mobility has a very weak pulse. Race gaps are widening.

The new federalism in part is being born of necessity. National politics is in ruins, and national institutions are weakened by years of short-termism and partisanship. Power, finding a vacuum in D. C., is diffusive. But it may also be that many of the big domestic-policy challenges will be better answered at a subnational level, because that is where many of the levers of change are to be found: education, family planning, housing, desegregation, job creation, transport, and training. Amid the furor over Common Core and federal standards, it is important to remember that for every hundred dollars spent on education, just nine come from the federal government.

We may be witnessing the end of many decades of national-government dominance in domestic policy-making (the New Deal, Social Security, Medicare, welfare reform, Obamacare). The Affordable Care Act is important in itself, but it may also come to have a place in history as the legislative bookend to a long period of national-policy virtuosity.

The case for the new federalism need not be overstated. There will still be plenty of problems for the national government to fix, including, among the most urgent, infrastructure and nuclear waste. The main tools of macroeconomic policy will remain the Federal Reserve and the federal tax code. But the twentieth-century model of big federal social-policy reforms is in decline. Mayors and governors are starting to notice, and because they don't have the luxury of being stuck, they are forced to be entrepreneurs of a new politics simply to survive.

VIII. It is possible for America to recover its earlier dynamism, but it won't be easy.

The big question for Americans is: Do you really want to? Societies, like people, age. They might also settle down, lose some dynamism, trade a little less openness for a little more security, get a bit stuck in their ways. Many of the settled nations of old Europe have largely come to terms with their middle age. They are wary of immigration but enthusiastic about generous welfare systems and income redistribution. Less dynamism, maybe, but more security in exchange.

America, it seems to me, is not made to be a settled society. Such a notion runs counter to the story we tell ourselves about who we are. (That's right, we. We've all come from somewhere else, haven't we? I just got here a bit more recently.) But over time, our narratives become myths, insulating us from the truth. For we are surely stuck, if not settled. And so America needs to decide one way or the other. There are choices to be made. Class divisions are hardening. Upward mobility has a very weak pulse. Race gaps are widening. The worst of all worlds threatens: a European class structure without European welfare systems to dull the pain.

Americans tell themselves and the world that theirs is a society in which each and all can rise, an inspiring contrast to the hereditary cultures from which it sprang. It's one of the reasons I'm here. But have I arrived to raise my children here just in time to be stuck, too? Or will America be America again?

Editor's note: This piece originally appeared in Esquire.

“There is room for everybody in America,” wrote French-American author Hector St. John de Crèvecœur in 1782’s Letters from an American Farmer.

Like most of the founding generation, Crèvecœur believed the sheer size of the new nation meant for a prosperous future. But he was also celebrating an attitude of openness, a willingness to embrace new citizens from around the world into what he called the “melting pot” of American society.

The embrace of openness has survived, in spite of occasional outbreaks of anti-immigrant sentiment, for the intervening two and a half centuries. The United States remains an immigrant nation, in spirit as well as in fact. (A fact for which, as an immigrant from the Old Country, I am grateful). My wife is American, and my high schoolers have had U.S. passports since being born in London. Right now I'm applying for U.S. citizenship. I want America to be my home not just my residence. My story is of course very different to most immigrants - but the point is, all of our stories are different. What unites us is our desire to be American.

But this spirit may be waning. Thanks only in part to Donald Trump, immigration is near the top of the political agenda – and not in a good way.

Trump has brilliantly exploited the imagery of The Wall to tap into the frustrations of white middle America. But America needs immigration. At the most banal level, this is a question of math. We need more young workers to fund the old age of the Baby Boomers. Overall, immigrants are good for the economy, as a recent summary of research from Brookings’ Hamilton Project shows.

Of course, while immigration might be good for the economy as a whole, that does not mean it is good for everyone. Competition for wages and jobs will impact negatively on some existing residents, who may be more economically vulnerable in the first place. Policymakers keen to promote the benefits of immigration should also be attentive to its costs.

But the value of immigration cannot be reduced to an actuarial table or spreadsheet. Immigrants do not simply make America better off. They make America better. Immigrants provide a shot in the nation’s arm.

Immigrants are now twice as likely to start a new business as native-born Americans. While rates of entrepreneurialism are declining among natives, they are rising among immigrants. Immigrant children typically show extraordinary upward mobility, in terms of income, occupation and education. Among children born in Los Angeles to poorly-educated Chinese immigrants, for example, an astonishing 70% complete a four-year-college degree.

As the work of my Brookings colleague William Frey shows, immigrants are migrants within the U. S., too, moving on from traditional immigrant cities — New York and Los Angeles — to other towns and cities in search of a better future.

New Americans are true Americans. We need more of them. But Trump is tapping directly and dangerously into white fears of an America growing steadily browner. According to a 2011 Pew Research Center survey, more than four in ten white seniors say that a growing population of immigrants is a "change for the worse;" half of white boomers believe immigration is "a threat to traditional American customs and values."

Immigration gets at a deep question of American identity in the 21st century. Just like people, societies age. They might also settle down, lose some dynamism. They might trade a little less openness for a little more security. In other words, they get a bit stuck in their ways. Immigrants generate dynamism and aspiration, but they are also unsettling and challenging.

Where this debate ends will therefore tell us a great deal about the trajectory of the nation. An America that closes its doors will be an America that has chosen to settle down rather than grow, allowing security to eclipse dynamism.

Disruption is not costless. But America has always weighed the benefits of dynamism and diversity more heavily. Immigration is an important way in which America hits the refresh button and renews herself. Without immigration, the nation would not only be worse off, but would cease, in some elemental sense, to be America at all.

Editor's note: This piece originally appeared in Fortune.