John McCain had promised to bring up Barack Obama's ties to former Weather Underground member Bill Ayers at tonight's debate, and he delivered on that promise.
Moderator Bob Schieffer referenced Ayers, but not explicitly. It was up to McCain to use the name, and though it seemed at first as if he wouldn't, he finally did. For the most part, though, the moment -- not surprisingly -- was anticlimactic, without any real fireworks. McCain did do a good job of slipping in the attack somewhat gently (at least as gently as possible, given the very nature of the subject) by saying he doesn't care as much about Ayers himself as he cares about what he says are unanswered questions about the relationship between Ayers and Obama. And he said what he needed to say, making sure to mention that though he may not be in the Weather Underground anymore, Ayers is not repentant about his actions in the past.
On the other hand, Obama did a good job of knocking McCain off his game, making the question more about whether McCain's criticism was true than about the criticism itself, and McCain had trouble recovering.