Sept. 2: Split Verdict in Polls on Romney Convention Bounce
fivethirtyeight.blogs.nytimes.com
My view is that the consensus of evidence so far points toward Mitt Romney having received a small bounce in the polls of perhaps two or three percentage points from the Republican convention in Tampa, Fla.
Oddly enough, however, you can’t really find a poll that seems to reflect a 2- or 3-point bounce exactly. Instead, there have been some polls where Mr. Romney’s bounce has been a bit larger than that, and others where there is little sign of a bounce at all.
On the favorable side for Mr. Romney is the Rasmussen Reports tracking poll, which now shows him four percentage points ahead of President Obama. That represents a 6-point swing toward Mr. Romney compared with the poll Rasmussen Reports released immediately before the convention, although the bounce is smaller (about three percentage points) measured relative to the long-term average of their surveys.
An online national tracking poll from Ipsos also shows a bounce for Mr. Romney, although its magnitude has been shifting a bit from day to day. Based on the latest iteration of the poll, the race is now tied among likely voters at 45 percent each, reflecting a 4-point swing toward Mr. Romney from Ipsos’s poll before the convention. And the shift has been larger — a net of seven percentage points toward Mr. Romney — in the version of the poll that tracks the preferences of registered voters instead.
But there are also two clearly unfavorable data points for Mr. Romney. One is the Gallup national tracking poll, which still shows Mr. Obama with a 1-point lead — actually a bit worse for Mr. Romney than Gallup’s last survey before the convention, when he had led by one point.
Gallup’s survey still contains a fair number of interviews that were conducted before the convention began, and there is a bit of a silver lining for Mr. Romney in that Mr. Obama’s approval rating ticked down in the poll on Sunday. Since Gallup’s approval ratings are based on a 3-day polling average while their horse race numbers are based on a 7-day average, that could indicate Mr. Romney may still gain a bit of ground in the poll once it fully rolls over to post-convention interviews.