How much damage will Obama suffer from his lackluster performance in last night’s debate? Probably not much. I expect Romney to get no more than a 1 to 2 percent post-debate bounce/gain in the national and battleground state polls. Here is why.
According to Nate Silver’s analysis, the winner of a presidential debate typically gets very little bounce in the polls from winning the debate, usually only a little over 2 points. Clinton did the best against Bush in 1992 in their second debate, getting a 4 point bounce.
So, let’s assume that Romney will get a 3 point bounce from his performance which would be better than average bounce but not as much as Clinton.
Yesterday, Nate Silver had the average of the recent national polls giving Obama 51.8% to 46.8% for Romney or a 5 point lead. A 3 point debate bounce would allow Romney to close the gap, but Obama would still lead by 2, 51.8% to 48.8%. Statistically, Romney could get a tie but not much more.
Of course the Electoral College vote is what really matters. Romney has to win 270 electoral votes to win and three states are critical—Florida, Ohio, and Virginia. It is very unlikely that Romney can get the 270 electoral votes he needs without carrying at least two of these three states. Currently Obama leads in all three states by a margin of 2.2% to 5.6%.
Let’s assume Romney gets a 3 point debate bounce against Obama in all three states.
Now: Obama 49.5%, Romney 43.8%--Obama leads by 5.6%
Post Debate: Obama 49.5%, Romney 46.8%--Obama leads by 2.6%
Now Obama 48.2%, Romney 44.6%--Obama leads by 3.6%
Post Debate: Obama 48.2%, Romney 47.6%--Obama leads by 0.6%
Now: Obama 48.3%, Romney 46.1%--Obama leads by 2.2%
Post Debate: Obama 48.3%, Romney 49.1%--Romney by 0.8%
In short, if Romney gets a better than average post-debate bounce in the polls, he can close the gap possibly to a statistical tie nationally and in two of the three critical battleground states and move ahead of Obama in Florida but well within the margin of error.
Of course, this assumes that 100% of the roughly 5% undecided/persuadable actually watched the debate which isn’t likely. According to a Washington Post/ABC News poll only 32% of persuadable/undecided voters were very interested in last night’s debate. This suggests that most of the undecided didn’t tune in and thus never witnessed Romney’s performance. Lack of interest by nearly a third of the persuadable will most likely cost Romney 1 or 2 points from his possible 3 point gain. See: http://www.washingtonpost.com/blogs/the-fix/wp/2012/10/03/who-wont-be-watching-the-debate-persuadable-voters/
Bottom Line: I predict the polls will tighten over the next few days with Romney getting a 1% to 2% bounce. Only time will tell whether he will be able to keep that gain or not.