Mitt Romney gained further ground in the FiveThirtyEight forecast on Monday, with his chances of winning the Electoral College increasing to 25.2 percent from 21.6 percent on Sunday.
The change represents a continuation of the recent trend: Mr. Romney’s chances were down to just 13.9 percent immediately in advance of last week’s debate in Denver. He has nearly doubled his chances since then.
But the gains that he made on Monday in particular were all because of a single poll.
We’ll talk about that poll — a Pew Research poll that gave Mr. Romney a 4-point lead among likely voters — in a moment. But let’s first consider the day’s worth of polling without it, which was pretty mixed for Mr. Romney.
The most unfavorable numbers for Mr. Romney came in the national tracking polls published by Gallup and Rasmussen Reports. Both showed the race trending slightly toward President Obama, who increased his lead from 3 points to 5 points in the Gallup poll, and pulled into a tie after having trailed by 2 points in the Rasmussen survey.
In both cases, the numbers looked more like pre-debate data than the stronger numbers that Mr. Romney has been receiving since then. On average between the Democratic convention and the debate, the Rasmussen poll showed Mr. Obama with a 0.7-point lead (the Rasmussen poll is Republican-leaning relative to the consensus), while the Gallup poll had Mr. Obama ahead by an average of 3.4 points.
A third national tracking poll, an online tracking poll published by the RAND Corporation, showed essentially no change from Sunday. All of this seemed to be consistent with a story in which Mr. Romney’s debate bounce was receding some. (A fourth tracking poll, from Ipsos, had not been published as of the time we ran our forecast on Monday.)
The swing state polls published on Monday might best be described as being OK for Mr. Obama. He led in polls of Colorado, Iowa, Pennsylvania and Virginia, and in two polls of Michigan. In all cases, Mr. Obama’s lead was small. However, this particular group of pollsters had shown reasonably unfavorable numbers for Mr. Obama in the same states before. Three of the polls actually moved toward Mr. Obama from the numbers that the same polling firms had published before the debates.
Remember it’s one thing to give a poll a lot of weight, and another to become so enthralled with it that you dismiss all other evidence. If you can trust yourself to take the polls in stride, then I would encourage you to do so. If your impression of the race is changing radically every few minutes, however, then you’re best off looking at the forecasts and projections that we and our competitors publish, along with Vegas betting lines and prediction markets.
You can read more of Nate Silver’s analysis here….