I wouldn’t take this prediction to the bank if I were a betting man. But, like co-blogger David Bernstein, I give Obama a slight edge, perhaps a 60-65 percent chance of victory. In the contest between national polls favoring Romney and battleground state polls favoring Obama, I give slightly greater credence to the latter. My main reason for doing so is that their results have been more consistently favorable to Obama than the national polls have been for Romney. In addition, there is a nontrivial chance that Obama could win the electoral college while narrowly losing the popular vote. I also give some weight to the majority view among mainstream pollsters, which seems to be that Obama is more likely to win than not. On technical questions like this, I try to give some deference to expert opinion, unless there is strong evidence of bias or ulterior motives. And I am skeptical of claims by some conservatives that the professional pollsters are in the tank for Obama.
On the other hand, it’s certainly possible that the pollsters’ likely voter models are just slightly skewed in Obama’s favor. In a very close election like this one, even a 1-2 point skew could lead to an incorrect prediction as to the outcome. Dan McLaughlin of Red State makes an interesting case for that view in a series of posts (see here and here). Notice that McLaughlin is not claiming that Nate Silver and other analysts who predict an Obama victory are a bunch of idiots whose models are radically deficient, or a bunch of shills for the Democrats. Rather, he seems to be saying that Silver has a pretty good model that is slightly off – enough to make a wrong prediction in a close election. Silver [...]