I generally agree with this NYT analysis of last night's debate, but I can see how the McCain camp would be frustrated with this passage:
Mr. McCain, after starting off comfortably, seemed increasingly inconsistent and testy as the debate wore on. At one point he challenged Mr. Obama about whether he had ever stood up to leaders in his party — reflecting the concern among many voters that a President Obama and a Democratic-led Congress would impose one-party rule on the nation.
Mr. Obama replied that he had supported tort reform, to the annoyance of many Democratic trial lawyers. But then Mr. McCain did himself little good by sounding churlish as he muttered “an overwhelming vote,” and then sounded like a schoolteacher as he added, “Senator Obama, your argument for standing up to leaders of your party isn’t very convincing.”
The fact is, Obama's answer wasn't so impressive. He doesn't, in fact, have much record of challenging his party's orthodoxy. (Obama also mentioned his support for charter schools and performance-based teacher pay, saying those positions alienate the teachers unions. But in fact Obama is quite popular with the education establishment.)
You can argue that the act of "challenging" one's own party is overrated. But it's a reasonable debating point, especially given the prospect of large Democratic majorities in both houses of Congress. And it does seem that McCain had a decent point here--substantively won the exchange, in fact--but then lost it in the press on style points.
Maybe that's just how it goes, though. Ask Al Gore about those sighs.