There's no question that the preponderance of the polling evidence indicates that Obama is well positioned to cruise to a comfortable victory, and even stands a chance of blowing McCain out of the water.
Which isn't to say that there's no room to think that the race is much closer than it appears. A handful of polls have consistently shown McCain to be within striking distance. Most prominent among these is probably the tracking poll run by the Associated Press, but there are others. How does one decide which polls to trust?
Nate Silver's work at fivethirtyeight.com has shed important light on the question. Surveying the various polls, Silver has been able to demonstrate that the differences between them boil down to differences in their likely voter models. The short story is that polls lean Republican to the extent that they assume that the 2008 electorate will look like the 2004 electorate, and lean Democrat to the extent that they predict higher turnout among African Americans and new voters.
For prognosticatin purposes, what this means is that we've got to ask whether we believe that the Obama campaign is going to be able to get its voters to the polls. I'd say it's a pretty good bet. Speaking anecdotally, it's pretty clear that the voter registration and turnout effort on campus here in Ann Arbor is orders of magnitude beyond what we've seen in other years. You already knew Obama was going to win Michigan, but there are students everywhere. How many student votes will Obama pull out of the research triangle in North Carolina? I'd guess a lot.
What about the more traditional swing states? Here are a couple of data points worth noticing. In Ohio, African American's make up 12% of the population but made up only 10% of the electorate in 2004. In Florida, African Americans make up nearly 16% of the population but were only 12% of the 2004 electorate. Whatever else you believe about Obama's ground game, surely African Americans will vote in higher numbers than in 2004.
Which brings us to the official prognositcations. My optimistic prognostication puts Obama ahead with 371 electoral votes. My worst case gives Obama 278 electoral votes. Between them, I'd bet on wild optimism. What say you all?