I'm coming to it a few days after the fact, but this nugget from Newsweek's behind-the-scenes campaign account caught my eye:
McCain also was reluctant to use Obama's incendiary pastor, the Rev. Jeremiah Wright, as a campaign issue. The Republican had set firm boundaries: no Jeremiah Wright; no attacking Michelle Obama; no attacking Obama for not serving in the military. McCain balked at an ad using images of children that suggested that Obama might not protect them from terrorism. Schmidt vetoed ads suggesting that Obama was soft on crime (no Willie Hortons). And before word even got to McCain, Schmidt and Salter scuttled a "celebrity" ad of Obama dancing with talk-show host Ellen DeGeneres (the sight of a black man dancing with a lesbian was deemed too provocative).
One thing that puzzled me throughout the campaign was how genuinely aggrieved the McCain people would get when accused of playing dirty. (Which, between the shameful ad on Obama's support for kindergarten sex-ed, the Bill Ayers smear, the "socialist" charge, etc., they absolutely were.) They'd invariably hit back with a really righteous sense of outrage, whereas the typical Republican operative in that position goes kind of shifty on you, or even acknowledges what he's doing with a knowing smirk.
This item gives you some insight into where that came from: The McCainiacs thought they were doing the stand-up thing by ruling out certain below-the-belt accusations and insinuations. Of course, rejecting some ugly attacks in favor of others doesn't exactly speak to your integrity. But you could see how it would make someone think they were choosing the path of righteousness.