McCain-ocrats vs. Obamacans
Another writer today has a column out suggesting that the Dem crossover for McCain will be as strong as the GOP crossover for Obama. She doesn't have any solid numbers, except that "20% of white Clinton voters" say they might vote for McCain. That sounds impressive, but when you look at it there are an awful lot of limiters in that statement. My impression is that while many Clinton voters are pissed off now, if Obama were actually the nominee they would, in a sense, get over it and vote the party line.
It's not much different than the Romney supporters who swore they'd never vote for McCain or Huckabee because they didn't like the attacks on Romney's history or his Church. But it's only been a month or so and already I don't know a single Romney supporter who's seriously considering supporting either Obama or Hillary.
So, while it's true that McCain will certainly have some cross party support, I think it's a bit much to assume that he's going to run away with the moderate Democratic vote.