DIRTY CAMPAIGNS....Brad DeLong comments on the 2008 campaign:
Yes, John McCain ran a dirty campaign. But it was a less dirty campaign than any Republican has run since... well, since the memory of man runneth (with the possible exception of Ford 1976). The difference this year was that for some reason this year a fraction of the mainstream press called them on it rather than ignoring it entirely.
I have my doubts that the media per se was the difference this year. For what it's worth, I think the difference is that in past presidential elections most of the really vile campaigning not all, but most was either kept under the radar or left to surrogates. Plausible deniability was maintained for the worst of it. This year, for some reason, the McCain campaign itself was willing to conduct a lot of its sleazy attacks publicly in its own name, and this opened them up to media criticism in a way that previous campaigns managed to avoid. I don't know why they did this. I'm not sure that Brad is right about the relative civility of McCain's campaign in any case, but there's not much question that McCain's eager public embrace of slime made his campaign seem worse than it had to. I don't really have a good theory to explain why they did this.
POSTSCRIPT: I should add that I don't mean to imply this is the whole story. It's true that the media liked Obama and treated him pretty easily. I imagine this was partly because so much of the anti-Obama stuff was so plainly crazy (he's a Muslim, he's a black nationalist, his birth certificate was forged, etc.) and partly because they were being extra careful not to buy into any criticism that seemed even arguably racially motivated. And they were probably harder on McCain than normal because they felt like their hero from 2000 had fallen to earth.
In the end, though, despite constant kvetching from conservatives, the media did report on Jeremiah Wright and Bill Ayers and Joe the Plumber and all that. And it just didn't stick. Who knows why? For whatever reason, the public just wasn't in the mood for this brand of BS this year.