I'd vote for McCain over any Dem. I'm not fond of him, and there's no way the base would select him, but in the odd event he does get the nomination, I'd enthusiastically vote for him over anyone the moonbats would offer. The Presidency is more than just one man--it's a list of appointments to the Government. Any GOP president, no matter how "liberal" he may be, will have to appoint members from his party to various positions. Some of them, from a "liberal" GOPer, will be the like of David Souter--others, won't be. And that would be the difference, having a Gov't mixed w/ a couple of Souters, or a Gov't composed entirely of Jamie Gorelicks and Sandy Bergers.
A McCain Presidency would be a dismembered limb. A Hillary Presidency would be a disembowelment. Hopefully it won't come to that, but if its between that choice, one must be chosen. Sitting out and pouting is support for the disembowelment.
That's the argument I'd have with myself, and that's the same conclusion I'd reach: it's not a perfect world, but it would be a heck of a lot worse with Hitlary at the helm.