The lesson for 2012, for cynics at least, is not that Republicans should vote for Mitt Romney (or any other Republican) because his policies will create jobs and get the economy moving again — but that when the economy really gets moving again, Americans will ascribe those advances to Republican policies. Likewise, if Obama stays in office for another four years, odds are good — though perhaps not great — that the economy will eventually start to get better and Americans will give him credit for a rebound he in fact delayed more than created.

Now obviously it’s all more complicated than this. Presidents do in fact do things that affect the long-term trajectory of the economy, for good or for ill. And they do other things that are very important too (the idea that we elect presidents to “run” the economy is a very recent notion).

Still, there’s reason to believe that ideological realignments in this country are not necessarily the product of careful analysis and rigorous reasoning. Rather, they are the result of people assigning blame to the guy that just happens to be in charge when the data hits the fan.