Nate Silver blog, 10/25 -- "Oct. 24: In Polls, Romney’s Momentum Seems to Have Stopped"

Mr. Romney clearly gained ground in the polls in the week or two after the Denver debate, putting himself in a much stronger overall position in the race. However, it seems that he is no longer doing so.

Take Wednesday’s national tracking polls, for instance. (There are now eight of them published each day.) Mr. Romney gained ground in just one of the polls, an online poll conducted for Reuters by the polling organization Ipsos. He lost ground in five others, with President Obama improving his standing instead in those surveys. On average, Mr. Obama gained about one point between the eight polls.

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The trend could also be spurious. If the race is steady, it’s not that hard for one candidate to gain ground in five of six polls (excluding the two that showed no movement on Wednesday) just based on chance alone.

What isn’t very likely, however, is for one candidate to lose ground in five of six polls if the race is still moving toward him. In other words, we can debate whether Mr. Obama has a pinch of momentum or whether the race is instead flat, but it’s improbable that Mr. Romney would have a day like this if he still had momentum.

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