Barring a outlandish victory like 70/30, the number of delegates won at this point borders on meaningless. It's all about being able to make an argument to the superdelegates at the convention that carries some depth and weight, and a California victory adds both of those.
There are really only three ways left that Bernie can become the Democratic nominee, each with a smallish probability of coming to fruition.
- He wins the remaining states by such a large margin that he takes the outright lead in pledged delegates. Less than a 1% chance. Not happening.
- Hillary continues to drop relative to Trump (probably due to more email drip-drip-dripping) while Bernie continues to outpoll him, and, with a recent California victory in his pocket, the superdelegates decide at the convention that Bernie is the best candidate to beat Trump and hand him the nomination and thus overriding the popular vote. I'd say this happens only if Hillary is so clearly damaged beyond repair that it is obvious that the superdelegates' hands are being forced by Hillary and not the other way around. I'd say this has about a 10% chance of happening and something I predicted before New York. I'm not as confident as I was then but I haven't given up, either.
- By far his greatest chance is a Hillary indictment, or scathing exoneration that makes Hillary significantly more unelectable than she already is. I'd say this has about a 30% chance of happening. Even if she is indicted but it comes after the convention has been decided Obama and the rest of the powers that be could replace her with Biden or Kerry. Or hell, what about Michelle?
And there, in a nutshell, is his argument for staying in until the convention. And I'd say, with a 40% chance at the nomination, it's a pretty strong one, certainly stronger than Hillary had in '08 even though she was closer in the delegate count. Really, it all depends on how this email mess shakes out. I think even without them Bernie is the stronger candidate against Trump, but with them he becomes increasingly so by the day.