California with 52 percent, Nevada with 51 percent.

Hard to say, if you're talking what will happen at election time.
And what's the point?
Reagan didn't drop out when Ford was leading. Ted Kennedy didn't drop out when Carter was leading. Jesse Jackson didn't drop out when Dukakis was leading.
And Obama's lead over Clinton is far narrower than those of the eventual victors in any of these races.
Where will an Obama supporter go if Clinton wins? Where will a Clinton supporter go in the far more likely event that Obama wins?
Of course, the rancor between the two sides is dividing the Democratic Party. That's what party nomination campaigns do, like any campaign.
But given the choice, come election day, between sitting on your duff at home, and defeating the party of George W. Bush, I can't believe many Democrats will find petulance a stronger motivation than the opportunity to install change.
Of course, the future often surprises.

Not very likely given the facts on the ground. Even in Pennsylvania, Clinton's lead is slipping dangerously; if she wins there, it will be by a margin of a modesty that seemed inconceivable even two weeks ago.
She's basically toast.
(I'm not over the moon about this. I liked Clinton and Obama, both.)