Blumenthal watches the national polls (above is the current poll of polls, sans Rasmussen, since September 1, with maximal sensitivity to find any sudden trends):
[C]onsider the dozen or so new national polls released on Sunday. The results appear to be converging, as they often do in the final days of the campaign. A week ago, the margins separating the candidates varied between a 4-point Romney advantage and a 3-point Obama edge. Now the spread in the margins is narrower. Five of the polls show an exact tie, and seven give nominal advantages to Obama that are between 1 and 3 percentage points. The new surveys include the final national samples from the Pew Research Center, NBC/Wall Street Journal, CNN/ORC International and YouGov.
On the above graph, the president is now only 0.4 percentage points down from his implosion on October 3. Nate Cohn believes Obama's odds are good:
The polls are quite consistent and clear in the battleground states worth 270 electoral votes. With Obama above 49 percent in Nevada, Wisconsin, and Ohio, a wave of undecided voters can't flip the outcome. At this point, the polls must be wrong for Romney to prevail. The polls have been wrong before and they will be wrong again. The race is close enough for the polls to conceivably get one of those states wrong, but the odds are against it.
Kevin Drum accounts for polling error:
[S]uppose there is a systematic bias in the polls. How big would it have to be in order for Romney to win? This is what Sam Wang's "meta-margin" tells us, and it currently stands at 2.72%. That's how far off the polls would have to be—either because undecideds break heavily for Romney or because the pollsters' likely voter screens are wrong—in order for Romney to win, and it's a pretty big number. It's unlikely that either of these effects is anywhere near that large.
I've taught myself not to predict these things. But the data we have in front of us suggests a small late surge for Obama. But what I love about elections is the snap-moment of reality they reveal. That will always be a mystery to some extent. And that's something at this point – as we have only hours to the final stretch – worth treasuring a little.
We don't know.