× Expand (AP/Pablo Martinez and Evan Vucci)

On the question of whether presidential debates matter in the outcome of the election, the research is clear-they don't. A quick look at decades of Gallup polling shows little change in the election after the debates, and political scientists find that "the best prediction from the debates is the initial verdict before the debates." Put another way, if you want to know how the race will look after the debates, pay attention to what it looks like before the debates.

At most, there are two instances where you could plausibly say that the debates mattered for the election: the 1960 debates between Richard Nixon and John Kennedy, and the lone 1980 debate between Ronald Reagan and Jimmy Carter. And even then, this had more to do with the unique circumstances of both elections than it did with anything intrinsic to the debates.

To be fair to those who see these encounters as crucial events in the election, this is a counterintuitive position. After all, tens of millions of Americans tune in; 52.4 million people watched the first debate between Barack Obama and John McCain, 62.5 million the first debate between George W. Bush and John Kerry, and 46.6 million people the first debate between Bush and Al Gore. With viewership at that scale, how is it possible for the debates to have a marginal affect on the race?

The straightfoward answer is that the people who watch debates-a relatively small share of all adults-are also people who have some interest in politics. And for the most part, if you're interested in politics, you're not undecided about your vote. According to the latest Pew Research Center poll, only 7 percent of registered voters are "pure undecided." Five percent of registered voters are Obama voters who might consider a vote for Romney, and 3 percent are Romney voters who feel similarly about Obama. In all likelihood, the vast majority of debate-watchers are people who have committed to a candidate.

The presidential debates won't illuminate any issues, or tell us much that we haven't already learned. At best, they're an elaborate bit of political theater, where you can watch the candidates work to maintain their composure and-if you're creative-use the spectacle to devise a fun drinking game.