There is, as expected, a lot of discussion in the comments to my previous post about whether you can compare Jeremiah Wright to Bush's visit to Bob Jones university. In terms of saying "Which is worse", I'm not sure this is useful. Bush went somewhere reprehensible to campaign, once. Obama developed a close relationship with someone saying somewhat less reprehensible (but also, crazier) things, and apparently never called him out. Which is worse is bound to be about 100% correlated with your political persuasion. But I'm not interested in the moral equivalency; I'm interested in whether it is true that one party keeps its fringe at arm's length, while the other party embraces it. I think that for either party to say this requires some pretty energetic airbrushing of its own less salutary moments, and also, of course, a fairly hefty amount of bias as to what ideas you consider actually crazy, as opposed to merely a tad radical.
But a commenter raises an interesting point:
Regarding the equivalency between Bush's visit to Bob Jones and Obama's presence at J. Wright's church, the different contexts describe the differences between the Left and the Right, and the place of the extreme in both. Bush went to Bob Jones to campaign. In contrast, when Obama was campaigning in the primaries, he ran away from Wright. This does not make one morally better, but it demonstrates how acceptable the extreme is within the Right, as opposed to the Left.
On the other hand, the right basically forced Bob Jones to end its ban ten years ago. How good a metric is this for the current party? Plus Obama ran away when he had to--when it became a media stink. As did Bush, when Bob Jones became a publicity problem. A lot of the "My opposition is obviously worse" arguments seem to me to rely on fairly selective memory.