I can pretty much outsource to Kuttner, Sargent and Chait. Romney was like George W. Bush in the first Gore debate, a world-class bullshitter who combined lying and dissembling about his own plans with clever non-sequiturs. Only when it comes to forensics Obama is no Gore; he was OK at countering the lies and evasions he could expect, but has no instinct for the jugular at all with respect to openings that Romney left him. (For example, when Romney suggested that upper-class tax increases never balanced the budget, pointing out the tax increases that passed with no Republican support in 1993 in fact balanced the budget seems like a pretty obvious move.)
Does it matter? Probably not; debates don’t matter much and Obama’s risk-averse performance even makes some strategic sense. But I can’t say he did very well.
…as always, Pierce nails it: “The thing is, if you’re going to play rope-a-dope, sooner or later, you have to come off the ropes and throw a punch.”