Surprise, surprise.
It turns out that when a white woman is way behind a black guy and decides to make up ground by comparing him to Jesse Jackson and telling white rural and ethnic working class voters that he doesn't understand them, while his campaign tells its base that she can't be trusted, and will do anything -- including playing the race card -- the party starts to fracture.
Now, first waveexit polls show 60 percent of Obama voters in Indiana saying they won't be satisfied with Hillary and two-thirds of her voters in NC and Indiana saying they won't be satisfied with Obama. See here, also.
But remember: It's good for the party. Lots more registrations accompanied by racial polarization is a great tonic for a political party.