“The best argument against democracy is a five-minute conversation with the average voter.” – Winston Churchill

WASHINGTON — The 2012 presidential election looks like it could be a close one. When an election is tight, trying to understand voter behavior is all the more important.

What exactly is it that makes voters reward a challenger or punish an incumbent? Do they care about the unemployment rate, GDP or inflation? Are voters motivated by position papers or a candidate’s personal history? Is the electorate responding to slick TV ads or how the candidates performed in the debates?

It may be something else altogether.

Recent research has revealed that voter irrationality may be more arbitrary than we think. And in a razor-thin election just enough irrationality can make all the difference.

Just how irrational are voters? It is statistically possible that the outcome of a handful of college football games in the right battleground states could determine the race for the White House.

Economists Andrew Healy, Neil Malhotra and Cecilia Mo make this argument in a fascinating article in the Proceedings of the National Academy of Science. They examined whether the outcomes of college football games on the eve of elections for presidents, senators and governors affected the choices voters made.

They found that a win by the local team, in the week before an election, raises the vote going to the incumbent by about 1.5 percentage points.

When it comes to the 20 highest-attendance teams — big athletic programs like the University of Michigan, Oklahoma and Southern Cal — a victory on the eve of an election pushes the vote for the incumbent up by 3 percentage points. That’s a lot of votes, certainly more than the margin of victory in a tight race.

And these results aren’t based on just a handful of games or political seasons; the data were taken from 62 big-time college teams from 1964 to 2008.

The good news, we suppose, is that sports really can cheer us up and make the world seem like a brighter place. The sports fan is left happier and more satisfied all around, not just on the gridiron.

When you are feeling upbeat and happy, you feel more satisfied with the status quo in general. And feeling satisfied with the status quo makes you more likely to vote for the incumbent politician, even if that’s totally irrational.

The study’s authors control for economic, demographic and political factors, so the results are much more sophisticated than just a raw correlation.

They also did a deeper analysis that took into account people’s expectations. It turns out that surprise wins are especially potent, raising local support for incumbent politicians by about 2.5 percentage points.

This phenomenon isn’t limited to football. The authors also considered the 2009 NCAA Basketball Tournament and found broadly similar results.

It’s a sign of just how fickle we are and how much we can be a captive to our own moods.

The success of your local team is the electoral cousin of beer goggles: It can cloud your judgment and make you hate yourself in the morning. And that, as they say, just ain’t right.