While everyone judges whether Romney gets a 2 or a 6 point bounce, don’t forget that there is only a weak relationship between a candidate’s vertical leap and their performance in November. Instead, remember to follow a few potential beneath-the-hood bounces that might wind up mattering more in November.
1) Will Romney’s favorability ratings improve? He doesn’t need to be wildly popular, but he probably needs to get close to even in an average of polls. If he can’t do it after the RNC, that's a sign that Obama's attacks might be more durable than Republicans hope.
2) Can Romney consolidate the voters who outright disapprove of Obama’s performance? One of Romney’s true signs of weakness has been the discrepancy between his 46 percent ceiling in the RealClearPolitics average and Obama’s 48 percent disapproval rating. It would be surprising if he can’t close the gap after the RNC.
3) Can Obama improve his approval rating? Obama’s approval rating has been lodged beneath 50 percent for years, but a convention geared toward making the president’s case could plausibly move the numbers. Following Bush’s RNC in 2004, his approval rating ticked up from 49.5 percent on August 31 to 52.9 percent on September 9 in the RCP average.
4) Will the conventions influence the enthusiasm gap? The gap between registered and likely voters is a little larger than usual, and that probably has to do with a smaller share of Democrats and particularly non-white and young voters saying they’re enthusiastic or certain to vote in November. But many voters don’t start turning in until the conventions, which represent the first real opportunity for the campaigns to shift these numbers to their advantage.
5) Is there any movement in the convention states? The parties keep hosting conventions in battleground states under the assumption that the favorable media attention and outreach opportunities help the campaigns out in November. In 2008, there were news reports claiming that the McCain campaign felt well-positioned in Minnesota due to the convention, and Obama stayed above water in Colorado, even in the midst of McCain's post-convention bounce.