John McCain’s mantra tonight was simple: Barack Obama “doesn’t understand.” He repeated this line over and over, and at one point directly said that Obama “lacks the knowledge” to be president. But Obama demonstrated over and over that he does understand foreign policy. He has a better command of foreign policy issues than most presidential candidates (as does McCain.) McCain tried – and, I think, needed – to disqualify Obama as a foreign policy president, and I think he failed. McCain did land some blows, but Obama easily cleared the bar.

On the economic portion of the debate, McCain seemed to have one single idea: cut spending. He turned every question into a reason to cut spending, mainly earmark spending, which is a tiny percentage of the budget. He is unable to engage on the broader questions of the role of government in economic life.

--Jonathan Chait