I think Dana makes two very good points here. Indeed, not only are health exceptions popular, the dismissive tone of McCain's scare quotes were instructive in a way that (to put it mildly) isn't going to help him among moderate women. Obama was also clever to follow-up with the Ledbetter case, which McCain was equally dismissive about. I also agree that Obama's refusal to cede the moral ground on the abortion issue to McCain was important. It's true that I wouldn't be inclined to describe sex as "sacred" or to care whether a woman consulted her "religious adviser" before deciding about whether to continue her pregnancy -- but I'm not the median American voter. Sending comforting signals to committed religious voters in ways that don't compromise on substance is important.
The one thing I'd add is that McCain, as one would have expected, attempted to defend his highly unpopular "Roe should be overturned" view by saying that abortion policy should be "left in the hands of the states." This is, of course, a complete fraud, starting with the fact that McCain has voted for every federal abortion regulation to come down the pike. An even better way to point out the contradiction would have been for Obama to challenge McCain on his position that there should be a constitutional amendment making abortion illegal in all 50 states. This would force McCain to either defend an extremely unpopular policy that makes a complete hash of his "federalism" dodge or to repudiate a position that matters to a lot of his party's base. I'm not sure why Democratic candidates never attack this vulnerability. But otherwise, I think Obama did very well.
--Scott Lemieux