It’s typical for presidential candidates to receive a bump in the polls after their conventions, which give candidates a chance to present their message unimpeded, speak directly to their base, and try to woo undecideds without the distraction of a shared stage and opposing viewpoints.
According to Political Wire, all three major polling groups have shown Obama gained a larger bounce post-convention than Republican nominee Mitt Romney. Obama is leading Romney by two points according to Rasmussen and four points according to both Reuters and Gallup.
The GOP received what Princeton Election Consortium is calling a negative bounce — Democrats actually gained as a result of the party’s Tampa event.
[T]he GOP convention was of no help to them in the Electoral College. Indeed, it appears that the race shifted towards President Obama by 6-15 EV, or about 1.0% of Popular Vote Meta-Margin. From an analytical perspective, a negative bounce is quite remarkable because all the talk in recent weeks has been of bounces being smaller or zero, but always in the hosting party’s favor. It is all the more remarkable because of the relatively small number of state polls over the last week, so that the Meta-analysis’s inputs have not fully turned over (for discussion see comments). So the negative bounce may be larger than what is shown in the graph.
If both conventions somehow translated into gains for Obama, it will be interesting to see how those gain change over time as “post-convention bounce” wears off, as it traditionally has in past cycles.