WE HAVE discussed at length the claim, popular among political scientists, that the effect of campaigns on presidential contests is rather small, at least when compared to the importance of prevailing economic conditions. The simplistic but roughly accurate rule of thumb I tend to repeat at parties is that, in presidential elections, the incumbent wins as long as he's passably popular and the economy has been growing, and he loses if he isn't and it hasn't. Alan Abramowitz, a professor of political science at Emory, voiced his discipline's conventional wisdom this summer to the Washington Post:

“When you’re in the middle of a campaign, there’s a tendency for people, especially the media, to overestimate the importance of certain events,” Abramowitz says. These include high-profile gaffes, vice presidential selections, controversial ads and other moments that capture so much attention. Except, he adds, “those things have no measurable impact [on voters’ decisions]. The media are interested in getting people’s attention, but a lot of the stories you read or see are focusing on things that are trivial. The way campaigns play out is largely determined by fundamentals.

So I was amused, and slightly put out, when, in the wake of the re-release of Mitt Romney's infamous 47% remarks, a number of prominent figures in the media leaped at the chance to overestimate its significance. Here's what David Brooks said about it:

Let this be a lesson to you political scientists: Campaigns matter. The things that have shaped this campaign are not things you can put into a model. It’s been the character of the candidates — doubts about Romney’s authenticity — and the quality of the campaigns — Obama’s ability to segue from the Bain attack to the Medicare attack to the more general character attack in a coherent way, step by step.

I refused at the time to admit that "campaigns matter" in the way Mr Brooks suggests not because so-called gaffes don't move the polls, but because candidates and campaigns of roughly equal quality each get their share of bad breaks. That's why I don't think Mr Romney's victory in this week's debate, if it should turn out to improve his standing in the polls, would demonstrate that "debates matter" so much as to confirm that Messrs Romney and Obama are indeed quite equally matched, and that over the course of the campaign, we can expect each camp to more or less neutralise the other. Which leaves the "fundamentals" most likely to determine to the winner.

I prefer this sort of distant, reductionist, structural approach to analysing the race because there's little reason to believe in the validity of the implicit theories or "models" lurking behind pundits' gut judgments. When I heard Mr Romney's 47% comments, I thought "Oooh, he's toast!" and then I stopped myself and acknowledged that I actually have no rational basis for believing that his remarks would in the final analysis hurt Mr Romney at all. What percentage of undecided or weakly-decided swing-state voters ever caught wind of Mr Romney's embarrassing chat? I didn't know! Of those who became aware of it, how many cared? I didn't know! So why did I think "Oooh, he's toast!" Because I am human, and I make most judgments and decisions on the basis of crackpot hunches, the underlying logic of which is almost completely inscrutable to me. Last night, I was delighted to witness Entertainment Tonight's hard-hitting segment on Wednesday's debate. Mr Romney was presented as the impressively presidential victor. Mr Obama, in stark contrast, came off listless, soporific and completely outgunned. The "body language analysis" portion of the segment was rather devastating. "Oooh, he's toast!" I thought, feeling suddenly excited by the prospect of a fresh "narrative" about a reinvigorated contest. I couldn't help it. I am what I am.

By the way, today's employment numbers probably come too late to make a significant difference in the election. So relax, people. The fundamentals have already spoken. All there is to do is wait to hear what they've said. Or don't relax. Invent lots of crazy stories, instead. Whip yourself into a lather. Get positively livid at the idiots on the stupid/evil team, as though the fate of the nation hangs on the self-righteous vehemence of your Facebook comments. Yes, let's do that. That sounds fun.