Jon Chait, contends that few of Mrs Clinton's blue-collar supporters would run over to John McCain's side if Mr Obama wins the nomination. Similarly, Mr Obama's supporters in the black community and in urban areas are unlikely to shun Mrs Clinton if she were to become the nominee. But which scenario is more likely. In other words, whose support of the party is more fleeting? The answer is obvious: Clinton's blue-collar supporters are the more politically tetchy of the two groups—the more likely to change sides. And that matters a great deal in close, must-win states like Pennsylvania and Ohio. Advantage Clinton. [Emphasis added.]
I'm on the fence about what happens to the black vote should Clinton get the nomination. Part of me wonders whether black voters will simply sit out the general election in disgust if Hillary's the nominee, seeing as how the only way she'll get the nomination at this point is if the superdelegates give it to her. If you think Jim Clyburn et al are pissed at the Clintons now, how are they going to feel after the elites come in and overturn the will of the people?
Then again, there'll be enough time between when the nomination is decided (which, at the latest, will be in August) and November that tempers could calm in the interim. Especially if black leaders get behind Clinton. The most important of those black leaders will be Obama--and I have a hard time envisioning a situation in which he wouldn't actively back Clinton's candidacy should she be the nominee. Part of that is because I think that--at a basic level--he's a decent guy and he realizes the stakes in the election. But, maybe more importantly, he's a young enough guy that, if he didn't, his future in Democratic politics would be kaput.
Anyway, it's an open question and one worth contemplating. I think it's a mistake to just assume that Clinton would hold the African-American vote as the Democratic nominee (as The Economist seems to); but I think that in the end she probably would.