Debates don't tend to fundamentally reshape presidential elections, but there's a chance that Romney’s historic performance might prove to be an exception. While it’s still early to judge the exact size and duration of Romney’s bounce, it has already given him his first lead in the national polls. As of last night, every post-debate national poll either shows a tied race or a slight Romney advantage, with Romney averaging a 1.4-point lead among likely voters.
But while there are not yet enough state polls to confidently judge whether Romney’s bounce cascaded across the electoral map, there are signs that Obama has fared slightly better in the battleground states than he has nationally. An equal number of battleground state polls show Obama or Romney ahead, even though Obama starts with more electoral votes and the majority of polls were conducted by firms typically producing Republican-leaning results (WAA, ARG, Rasmussen, and Gravis).
Yesterday's CNN and SurveyUSA polls in Ohio are potentially troubling signs for the Romney campaign. Heading into the debates, Obama led by a larger margin in Ohio than he did nationally, so Romney needed outsized gains in one of Ohio, Wisconsin, or both Nevada and Iowa to break Obama's easiest route to 270. If polls confirm that Obama maintains a slight lead in the key tipping point states, even at the height of Romney's post-debate bounce, it would be an indicator of Obama's resilience in perhaps 2012's most critical state. Certainly, new polls could show Romney holding an edge in Ohio, but so far there is not strong evidence that Romney has taken a lead in the Buckeye State.
Viewed collectively, the post-debate polls point toward a close race with Romney gaining an average of 3.4 points. Whether that's enough for Romney to take a lead depends in part on whether you thought Obama was up by 3 or 5 points prior to the debate, but it seems fair to assume that the race was roughly tied over the weekend. That assessment represents something of a compromise between split state and national polls, but there are not nearly enough national surveys to confidently argue that there's a big gap between the battlegrounds and the country as a whole.
While it’s clear that Romney made big gains following the debate, it remains to be seen whether Romney’s bounce endures into this week. Almost all of the polls were conducted in the days immediately following the debate, when Romney's bounce might have been at his highest. Very few polls have been conducted exclusively over the last few days, and those that have hint that Romney's bounce might be short-lived.
Yesterday, Gallup reported that their most recent samples show Obama returning to pre-debate levels among registered voters. For that reason, Gallup is arguably the best news that Obama has received since the debate, despite predictably showing Romney gaining about 5 points after transitioning to a likely voter model. Similarly, Rasmussen’s Sunday polls of Colorado and Iowa showed Obama doing better than their pre-DNC counterparts and Rasmussen’s tracker also shows Obama returning to his post-DNC average. PPP tweeted that while Romney fared well on Thursday and Friday in their polls of Wisconsin and Virginia, Obama did much better on Saturday and Sunday. These signs are all consistent with the possibility that Romney's gains have receded, even if they are insufficient to prove that Romney's bounce is over.
The hints of movement back in Obama’s direction may just prove to be static. But those hints are enough to justify waiting a few more days for polls conducted over the weekend before concluding that Romney’s performance resulted in a lasting and fundamental shift in the race. If Romney can hold his post-debate gains, the race would be quite close—as close as any election at this stage—with the exact favorite coming down to whether Romney can take a lead in critical states like Ohio.