It took me a while to read it, but Mark Schmitt's meditation on the Republican National Convention at the American Prospect site nicely captured the essence of the McCain-Palin campaign, as reflected in McCain's own acceptance speech:

[B]y stripping away in embarrassment all aspects of his own party, by declaring independence without new ideology, and allegiance to nothing but a self-defined notion of "Country First," it was McCain who was left standing alone, the raw individual, resting everything on his own story, his own honor, his own instincts. It was a far bigger claim than the man or his speech could deliver.

I'd note that McCain has added Sarah Palin's "own story, [her] own honor, [her] own instincts" to the rationale for the GOP ticket, but that's exactly why her selection represented a doubling-down of McCain's strategic gamble of posing as a "maverick" while championing Bush policies, not some audacious history-making tilt to the center. Picking Palin guaranteed him among conservative activists all the slack he needed to say and do whatever he needed to get elected. It was an added bonus that Palin herself is perhaps even more adept than her running-mate at using her "story" to disguise her actual views, which wouldn't command more than a small minority of voters if put to a direct test.