We don’t know whether the conventions will make a difference to who wins the election — but we do know that Barack Obama received a larger bounce from them than did Mitt Romney. (We’ll have to wait to see whether the bounce turns into a permanent bump.)

So future campaigns trying to derive lessons from the conventions will assume that whatever the Democrats did worked and whatever the Republicans did was unsuccessful. Odds are that campaign operatives will converge on an explanation, one that will prove hard to shake, whether true or not.

Watch carefully, then, for that explanation to start appearing. For example, Nate Silver suggests the difference might have been the timing (or at least that operatives will believe it was the timing): “Prediction: in 2016, the out-party won't want to hold its convention just one week before the incumbent's.”

Philip Klein has a different suspect: “Keep in mind that Romney's ads reflect his message. And that message fell flat at RNC, according to polls.”

I have no idea what it was. Maybe it was the hurricane, cutting down media coverage of the Republican convention. Maybe it was Clint Eastwood. Maybe Mitt Romney just isn’t likable – or perhaps the Democrats had a more likable roster of speakers. Maybe it was structural in a different way; Republican leaners had already come home to Romney, thanks to a very efficient media effort, but Democratic leaders had not yet rallied around Obama.

I’m rooting for a different lesson, however: that it’s a bad idea to base your convention theme around an out-of-context quote, and that it’s a bad idea for your vice presidential candidate to reel off one whopper after another in his convention speech – especially obvious lies that the media can’t help but pick up on.

Is that what hurt the Republicans? I have no idea. My best guess now is Obama having more low-hanging fruit to harvest than Romney, but that’s just a wild guess. However, I’m really hoping that the interpretation involving lazy mendacity takes hold, since it really would be nice if our politicians believed that sort of thing was punished.