It was, I think, his best debate in the campaign so far. The one-on-one format elevated him instantly and he commanded the stage and the occasion. Hillary Clinton did not do poorly. All her strengths were on show: the policy mastery, the gaffe-free talking points, the Clinton record in the 1990s. But that made his mastery all the more impressive. The good natured sparring helped him. He neutralized her on healthcare and simply cleaned up on the war in Iraq. But most crucial: he seemed like a president. He was already battling McCain. She was still pivoting off Bush. In his body language, he carefully upstaged her, without looking as if he were trying. By the end of the debate, he was pulling her chair back for her.

I'd say that he won the primary election tonight. She is still a formidable candidate and her massive institutional advantage may eventually give her the nomination. But she hasn't won this primary argument or this primary battle. If she becomes the nominee, it will be because she survived the primaries. He won them.

You know my bias. It's on my sleeve. But I've criticized Obama's performances in the past and couldn't find a flaw tonight. A good closer, as I've been told for over a year now. You can say that again.

(Photo: Spencer Platt/Getty.)

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