The latest crop of opinion polls has generally brought good news for Democrats. The Real Clear Politics average of all the national polls has given President Obama a slight lead, after this poll of polls had shown him trailing since Mitt Romney’s post-Denver debate comeback changed the race. Even more important, polls of likely voters in the battleground states have given the president leads in most of them. This caused New York Times blogger Nate Silver to double down on his forecast predicting an Obama win. According to Silver, Obama now has an 83.7 percent likelihood of prevailing on Tuesday.
We’ll leave aside the arguments about Silver’s odds-making, which depicts what even most liberals concede is an extremely close election as a near certain Obama win. Suffice it to say, as I wrote on Thursday, Silver’s belief that Obama had a field goal lead with 3 minutes left in the game (which he may now think is more like a 4-point lead with 2 minutes left) is based on a belief that the polls he trusts are accurate. On Saturday, however, he returned to the question that has to be haunting his readers: what if these polls aren’t accurate? While he admits the possibility, he thinks it unlikely that so many surveys could be in error. That seems logical, even persuasive. But the problem with that assumption is the same as it has been for the past month. Most of the polls showing Obama ahead either nationally or in some states reflect a common bias: their sample reflects a picture of the electorate that resembles the 2008 Democratic advantage. But this year we expect the gap in party identification to be smaller. In short, unless the Democrats match or exceed the massive “hope and change” surge of four years ago, then what Silver and the Democrats who look to his column for encouragement fear will be true: all the pro-Obama state polls are going to turn out to be quite wrong.



