I don't want to jinx anything (too late!) but the Rays prevailing over the Red Sox has given me hope about Obama's prospects...
Let me explain.
For tracking the polls, the best place by far is fivethirtyeight.com, which uses some hardcore statistics to combine polling and demographic data to forecast the election results. The guy who runs the site, Nate Silver, has a day job doing hardcore statistics for Baseball Prospectus. Way back in February, Nate forecast that the Rays would be the most improved team this year. And he was right!
In the ALCS (Nate was not so bold as to predict the Rays would make the post-season, let alone the World Series) the Rays were up 3 games to 1 against the Red Sox. Building a 7-0 lead in the 7th inning, the Rays were roughly where Obama is right now. But it ain't over til it's over. And the Red Sox came back and won the game. And won comfortably in Game 6. It looked like an epic collapse was at hand...but in the end, the Rays prevailed!
Similar to the calculation of safe lead in college basketball, an extremely unlikely series of events has to occur for McCain to prevail now. And the Rays/Sox showed us how unlikely that is.
(Of course, I probably jinxed everything now. But if Nate was right about the Rays...)