Tonight’s High-stakes Clash

As you watch this evening’s televised debate between Democratic President Barack Obama and his all-over-the-map Republican opponent, Republican Mitt Romney, keep in mind master poll-watcher Nate Silver’s remarks today in The New York Times:

If there is reason to suspect a rebound for Mr. Obama, it is probably based more on election fundamentals than the debates themselves. Mr. Obama’s approval ratings are just strong enough, and the economy has shown just enough resiliency, that he might be a narrow favorite on each basis. One function that debates can serve is to bring elections more into line with the fundamentals.

There is no evidence, incidentally, that the second presidential debate is any less important than the first one. On average, it has moved the polls by 2.3 percentage points in one direction or another--almost exactly the same as after the first debate, which moved them by 2.4 percentage points on average.

The third debate, however, has often had a more muted impact. The only significant change in the polls following the third debate was in 1992, when Mr. [George H.W.] Bush narrowed his deficit with Mr. [Bill] Clinton, and that may well have reflected a case of reversion to the mean.

Silver’s full piece is available here.