What blunder are you talking about? McCain has made dozens of major ones. Nominating Sarah Palin was IMHO one of the few things McCain has really done right; even if you didn't want to go that far, I can't see how you could regard her nomination as a bigger mistake than McCain's decision to vote for the Largest Bank Robbery In The History Of The World instead of voting Nay and naming the people who tried to load it with pork. Had he done that, he'd be poised for a landslide win.
I still think he'll pull it off. I don't think Hillary wants to openly side with McCain, but I think she will if she has to. She wants to be the queen of a powerful nation, not the ruler over a wasteland.
I didn’t say McCain was a brilliant choice as nominee for President either, but at least he isn’t laughable. His only hope of winning was with a very strong VP candidate — one that eliminated concerns about who would take the Prsidency if McCain’s age and health took him out, and eliminated concerns about his ability to pull in strong, knowledgeable, experienced people for his cabinet and other key positions. When he picked a joke like Sarah Palin as his VP candidate, reasonable people became alarmed as to what sort of people would be in other key positions in his administration. And while Obama is plenty worrisome to many reasonable people, he picked a decently experienced running mate, who wasn’t going to become the brunt of jokes all over the world. He demonstrated as much as possible at this stage, that people who are afraid he’ll fill his cabinet with wacko radicals, may not need to worry so much after all. Doesn’t mean he won’t pick a bunch of radicals after he gets to the White House, but at least with his only opportunity to make a pick before election day, he didn’t pick one. McCain had one chance to make a pre-election day pick and screwed it up badly, flat-out terrifying all the undecideds who are turned off by the GOP’s evangelical wing, and scaring off a whole lot more likely GOP voters by appearing to regard serious job qualifications as unimportant.