I do not agree with this. Obama has gone out of his way to make it easy on Clinton supporters to move on over to his camp when he wins, and while many Clintonistas will no doubt be devastated by Hillary losing it is unlikely to happen in a way that will make them bitter at Obama (irony intended). I just don't see a clear trajectory between being angry at the media for being mean to their candidate and then deciding not to vote in the general--this would only be the case if Clinton supporters were generally detached from politics and had been brought on board by Clinton's personality and policies, but that better describes Obama's support than Clinton's, and when it comes down to it, it won't be a hard choice for anyone who cares about women's rights: Obama is solidly pro-choice, McCain is not. This is, of course, not the only issue at stake with women's rights, but it is perhaps the most crucial one.
Oh, and all those polls where all those Clinton supporters say they'll vote for McCain instead of Obama in the general? Bollocks. Never happens. John McCain would be very, very lucky to snag 10% of Democrats. That's about what George Bush got in 2004, and aside from the Dixiecrats who are still registered Democrat but are de facto Republicans and some Hispanic crossover voters (and much smaller amounts of senior citizens and Black voters), the rest of the base ultimately held. Whenever there's a divisive nominating contest the people on one side say that they're going to sit out the general or vote for the other party, and they never do, with the only possible exception I can think of being 1972. Maybe 1980 (on the Democrats' side). But Bradley supporters eventually supported Gore, and Dean supporters made their way to Kerry after a time. McCain fans eventually found their way back to Bush. During the heat of a campaign, when it seems like your guy (or gal) is getting pummeled by their opponent, and all the while the media seems M.I.A., it shouldn't come as a shock that this scenario makes Candidate X's supporters angry, maybe even angry enough to say that they wouldn't support Candidate Y ever. Eventually, though, after X loses and some time passes, and the anger dissipates, it is only natural to reevaluate the situation. At the end of the day I'm hard-pressed to think of anything truly inexcusable that Obama did to Hillary, so there should be no eventual obstacle to most of HRC's contingent supporting Obama. Now, the conservative Democrats who think Obama's too liberal or too cosmopolitan (or too Black) might just find that McCain is more palatable, but McCain, as has often been noted, has never been attacked from the left. A conservative Democrat is still far to the left of a conservative Republican--Ben Nelson is about as conservative as they get among Democrats, and aside from social issues he's pretty much centrist. I doubt that socially conservative senior citizens in, say, Ohio are going to be as enthusiastic about McCain after they learn about his plans to shred Social Security, for example.
I will say this: if Obama manages to win Pennsylvania (and it's unlikely but not impossible, since stranger things have happened this election) he'll effectively knock Clinton out of the race. He will, to borrow a metaphor, reach escape velocity. And as soon as this nomination process ends Obama will get an enormous bump in the polls--he'll probably be up by 10-15 points over McCain again. I'm guessing. I'm going to go out on a ledge and say that Obama will narrowly win Pennsylvania. The narrative makes sense to me in my head. We'll see.
