Why are Obama voters so much more likely to vote for Clinton in November than vice-versa?

The number that is making waves from the exit polls is that less than half of Clinton supporters in both Indiana and North Carolina say they would vote for Obama in the general election. In Indiana, 33 percent said they'd vote for McCain and 17 percent that they simply wouldn't show up. In North Carolina, the number saying they'd cross over and vote McCain rose to 38 percent while 12 percent said they'd stay away. By contrast, 59 percent and 70 percent of Obama supporters in Indiana and North Carolina say they would vote Clinton in November. 

The Clinton camp will certainly hope that these numbers give the super delegates pause. But these same exits suggest that she has missed the chance to pile the pressure on Obama, with him emerging with a strengthened position in delegates and the popular vote after tonight.