Barack Obama

Relied on his early opposition to the war in Iraq to fight off an attack from Chris Dodd, but compounded his "experience" problem by rambling about foreign policy at times. If, as many think, he is not benefiting from all the focus on his national security credibility, then he had some bad moments. Referenced renegotiating NAFTA with a Canadian "president," which, in his case, counts as a conspicuous gaffe. Dodged a question about what to do should al-Qaeda take over Iraq following American withdrawal. Other than over-employing his standard verbal tic — punctuating his sentences with "Uhs" — he was mostly cool and collected. Talked masterfully and accessibly about trade and international economics. At the stadium, much of the crowd was palpably rooting for him; but on TV he didn't fully benefit from the Chicago home-field advantage.

—By Mark Halperin