Alan Abramowitz, a politics scholar at Emory University, has shown that summer head-to-head polls convey almost no information about the forthcoming election. (Subsequent head-to-head polls are not much better.) Instead, he has a simple “electoral barometer” that weighs together the approval rating of the incumbent president, the economy’s economic growth rate and whether the president’s party has controlled the White House for two terms (the “time for a change” factor). This laughably simple metric has correctly forecast the winner of the popular vote in 14 out of 15 postwar presidential elections.
Of course, it’s worth pointing out that Abramowitz’s “time for a change” factor alone correctly predicts 12 out of 15 postwar presidential elections, so those other two variables don’t really have to do much heavy lifting.
In any case, Abramowitz’s metric, which ranges from -100 to +100, gives John McCain a score of -60 this year, which means he’s as doomed as any candidate ever. This suggests two thing: (a) Obama is going to win a very convincing victory, and (b) the only real way for the McCain campaign to give itself a chance is by going negative early and hard. I’ll put money on both those things.