Nate Silver says polls have produced a "split verdict" so far:
[T]he one eventuality we probably can take off the table is the notion that Mr. Romney would emerge from his convention with unmistakable momentum, as Ronald Reagan did in 1980 or Bill Clinton did in 1992. His bounce may turn out to be “just fine” once we see a few more polls, and how the numbers move after Charlotte. But Mr. Obama is unlikely to make it easy for Mr. Romney.
Blumenthal points out that this year's polls are particularly hard to read:
As Professor Thomas Holbrook has shown, each party typically receives a bump from its convention, and the back-to-back timing of this year's conventions makes it much tougher to measure and interpret the shifts. Up until 2008, party conventions were held weeks or months apart, so pollsters were better able to examine each "bump" in isolation.
I know this is a very tight race in a highly polarized electorate and so we should not expect some dramatic movement. But by the Tuesday after the GOP convention, Obama is still ahead by a teensy margin in the poll of polls, (RCP gives him a 0.3 lead, Pollster gives him a a 0.1 lead (incuding Rasmussen); TPM's gives him a one point lead.) The bump that Romney has gotten is minuscule so far – less than one percent, unless the numbers change. McCain, in contrast, managed a gain of 5 points; and Obama gained around a point after his. That changed swiftly, of course. And maybe Charlotte will have Barbra Streisand talking to a chaise longue in prime time.
But that was a lost opportunity overall for Romney-Ryan. In this tight a race, the number of opportunities you can afford to squander are vanishingly small in number. And when you look at Nate's larger number, predicting November, including a variety of other factors, you see that in the past week or so, Obama's electoral college margin has grown by 9 since the GOP convention started.
I wouldn't be too thrilled if I were Eric Fehrnstrom.