I've seen similar reasoning to what C/W posted in comments on Monday (moderates who would support McCain over Clinton but not Obama) and interestingly I've also seen it used as ammunition for Clinton supporters who think Obama's popularity with right-leaning moderates who are currently propelling him will abandon him for McCain. I personally can't support it, of course; even though I thought McCain would be the "least-bad" president out of the abysmal GOP field, there's still no way you can support him over the boiled corpse of Anton Chekhov. Hopefully it doesn't come that.
I happen to think Obama runs rings around McCain in the general (it'll be pushing double digits, at least.) McCain is already starting to look like a crusty gaffe-prone fossil in comparison, and it'll only get worse as the months grind on. I don't even buy the pundit trope that his weighty foreign policy experience will submerge Obama; for McCain's record to have merit his positions have to actually be popular, which is a lot less promising now for Mr. Hundred Years.
While we're on the subject, a couple of words about what some have dubbed the "Obamacans," Republicans and right-leaning moderates who are crossing over to vote for Obama in the primaries and who have been used as ammunition at the pro-Clinton sites as proof that he lacks support of the "real" Democrats. This is a little perplexing, since Obama has also been the choice of many prominent liberal organs, including Moveon.org (via overwhelming membership polling) and The Nation magazine. Clinton seems to be outflanked on both sides in this race, so where exactly is her backing coming from?
The extent to which Obama is better on policy for liberals is quite small, though it is relevant especially, I believe, on many of the more peripheral issues. But I recall again something Molly Ivins said about Bill Clinton. During the 1990s, many left-liberals defended the Clintons reflexively out of the belief that they were getting a raw deal from the press and the Republicans. However, many of them silently resented the Clintons for the center-right takeover of the party, and now, presented with a legitimate contender to change the party's leadership, they've turned hard against the Clinton dynasty.
These people, despite their naive optimism in the Democratic party, still have a soul to save. Their fellow travelers, however, are the hardcore partisan Democrats, the Yellow Dogs, the red-hot blinkered, disciplined straight-ticket pulling party operatives. The kind of person whose entire political existence rises and falls with the Donkey, the Party itself is all the ideology they need. Politics, for them, is an interminable cricket match* of Our Team against Their Team, and the Clintons really are persecuted saints who have never done wrong because they won 'em for the Gipper**.
They've also got an infamous touch for picking losers, but, thanks in part to those Obamacans, their will is poised to be averted.***
*A redundancy?
**No, not THAT Gipper!
***It occurs to me that if the Democrats want to win more reliably they should follow the formula of a) seeing which candidate wins the primary among registered Democrats and b) electing the challenger. This is not, I should add, a Broderist fantasy about the "vital center." I think there are just as many, if not more, independents in this country who would be more accurately graphed to the general left of the Democratic Party. But that's another post.