The first ten of 20 Democratic presidential contenders who qualified for the party's first debate will take the stage in Miami on Wednesday evening for two hours of sparring moderated by NBC News' top talent.

The former vice president appeared surprised when he noticed Bernie's hand near his face as the Vermont senator over-extended into Biden's personal space.

Democrats debating in Detroit attacked their rivals more than the president, with moderates accusing ultra-liberals of making impossible promises and left-wingers calling for more radical plans.