After a decisive victory in the first presidential debate, Romney made big gains and inaugurated a new and close contest. But despite the clarity of Romney’s improvement, the exact source ofchange was never especially clear. Did Romney wipe away his extremist image and assuage the concerns of moderate voters disaffected with the state of the economy? Did the debate exacerbate the disappointment of the archetypical disappointed Obama voter that appeared to return to the president’s side amid a surge in economic confidence after the DNC? Did a decline in Democratic enthusiasm keep Obama’s supporters away from the polls and out of the likely voter models? Or was it some permutation of these credible options?
Whatever the verdict of tonight’s debate, there’s no question that the president’s performance was far stronger than the listless performance that first endangered his chances. The instapolls suggest that Obama edged Romney by a modest margin, not a landslide like the one that allowed Romney to improve by a net-4 or 5 points in the national polls (I admittedly didn't think the last debate would move the polls very much, but there's not much question that this debate seems less likely than the first debate to do so). But whether Obama improves in the polls depends, at least to some extent, on the source of Romney's gains following the first debate.
It's not hard to imagine a number of ways in which the debate could have helped the president. To the extent that Obama’s numbers faltered due to declining Democratic enthusiasm or response rates, one might expect the president’s energetic performance to rejuvenate Democratic enthusiasm. Similarly, if the perception that Romney was very moderate aided his post-debate surge, then Obama was probably aided by questions on social issues from a moderate crowd of well educated, socially moderate, New York suburbanites who helped push the debate toward a few social issues where Obama stands on relatively firm ground. Obama’s numbers might also improve if latent Obama supporters were simply disappointed by the president’s performance and less willing to offer their support to the president after a surprising defeat.
But if Romney’s gains were a product of a genuine shift in perceptions of Romney’s character, as suggested by several polls showing Romney with improved favorability ratings after the first debate, then Obama might not make many gains at all. If someone thought Romney was a good enough guy after the last debate, they probably still feel that way. Romney appeared capable of handling the presidency and an undecided voter who was previously open to supporting him would probably still be open to him tomorrow morning. Indeed, the CNN poll showed that an equal share of voters said they were more likely to support Romney and Obama after tonight's debate.
As a result, it wouldn't be wise to expect a big shift in the polls. After all, Romney's September standing was deflated after months of attacks, the DNC and the 47 percent comments and Romney surged to just over 47 percent of the vote--just about the share of voters who disapprove of the president's performance. Realistically, Romney won't lose many of these voters from this point out and he would probably win them back by the election if he did. And Obama isn't likely to return to his post-DNC standing of 49 or 49.5 percent of the popular vote, which probably reflected an unsustainably poor image of Romney and post-DNC momentum (unless Obama's losses were almost entirely due to Democratic enthusiasm or response rates). With Obama likely to fall in a narrow band between his post-debate 47 percent and his pre-debate 49 percent, any gains would be slight and potentially difficult to distinguish from static. Of course, if Obama could get his number back near 49 percent, that would still be significant and potentially difficult for Romney to overcome.