A while back, Ezra -- with the help of political scientists at Yale, UCLA, and George Washington University -- developed Wonkblog's very own presidential election model. It uses only three variables: economic growth during the first three quarters of the election year; the president's average approval rating as measured by Gallup in June of the election year; and whether or not a candidate is a member of the incumbent party.

Now that June is over, and the presidential approval data are in, the second of those variables is set for the 2012 election. I went through Gallup's tracking polls and found that Obama had an average approval rating of 46.46, virtually indistinguishable from George W. Bush's 46 percent June approval average in 2004. If second- and third-quarter economic growth stays at the first-quarter level of 1.9 percent, then the model predicts that Obama will win 82.5 percent of the time. Now, we won't know the second-quarter GDP numbers until the end of this month (and the initial figures are often wrong and are revised later), and the third quarter hasn't happened yet, so this could all change. But the president can find some comfort in the model now.