Money quote from his live blogging of the second debate:
This was, I think, a mauling: a devastating and possibly electorally fatal debate for McCain. Even on Russia, he sounded a little out of it. I’ve watched a lot of debates and participated in many. I love debate and was trained as a boy in the British system to be a debater. I debated dozens of times at Oxofrd. All I can say is that, simply on terms of substance, clarity, empathy, style and authority, this has not just been an Obama victory. It has been a wipe-out.It has been about as big a wipe-out as I can remember in a presidential debate. It reminds me of the 1992 Clinton-Perot-Bush debate. I don’t really see how the McCain campaign survives this.
I agree with Sullivan that Obama did well on the foreign policy questions.