You really can’t swing a dead cat around the chattering class these days without hearing about the “anti-incumbent” situation both political parties are facing this primary season and then this November. It’s really become the CW of a wide stripe of armchair political analysts, both the (over)paid type on TV and their counterparts at your water cooler. Judging by those two bellwethers, you’d think that most of the House was in serious danger of losing this fall.

I agree  that there’s something very interesting (and perhaps quite unusual) going on right now in American electoral politics. But I’m skeptical that “anti-incumbency” is the right word for it.The supposed evidence has significant flaws: there was no incumbent running in PA-12. there’s no incumbent running for Senate in Florida. There’s no incumbent running for Senate in Kentucky. The Pennsylvania Senate race featured an incumbent who was facing a new primary electorate for the first time.

But, you say, what about the other primaries?

Bennett did lose in Utah, no?  Mollahan lost in WV? This is true. Certainly the ousting of Bennett and Mollahan is some evidence, but since they were both bounced by very conservative candidates, it’s as much a data point for an ideological tide as an anti-incumbent tide. Is there any particular reason to think they lost because they are incumbents? Or did the Utah GOP and WV dems just prefer a more conservative candidate? Hard to say. I don’t think Bennett would have lost to a less conservative candidate. Or even one identical to him on an ideology scale. And yes, it’s plausible that his incumbent activites — voting for TARP, etc. — were his downfall. But again, those are policy positions that people actually have to think about and articulate. That’s far from a ‘throw the bums out’ mentality. Mollahan might have lost to anyone, but again we don’t know. His opponent ran against the health care bill. That’s not exactly “throw the bums out.” That’s a policy difference directed at the majority party.

I suppose “anti-establishment”  fits better than “anti-incumbent,” but even that I’m not sure it correct. The undercurrent seems to be an aggregate dissatisfaction with the current governing coalition, coupled with a lingering aggregate dissatisfaction with Bush-ism. And while anti-establishment and anti-incumbent have some Venn overlap, they are quite different in many respects. If one wants to link establishment state politics in Florida with establishment politics in Washington, they are more than welcome to do so. But that would a bridge to far for me: the vast majority of “outsiders” to take on DC have historically been exactly state establishment types.  So I don’t know.

Let’s get to the core logic and do some hypothesis testing. First, what would strong anti-incumbency look like in November? Well, for one, it would involve Members of Congress losing re-election (or retiring to avoid losing re-election) at a higher rate than normal. Second, it would involve these loses being rather uniformly distributed across both parties. Partisan landslides, no matter how many incumbents they boot out, aren’t typically due to anti-incumbent feelings; they’re usually due to dissatisfaction with the majority coalition.

And that leads to a key point: even if voters are fed up with both parties, if they only punish the Democrats this fall, that’s not anti-incumbency. That’s a partisan/ideological landslide.

So what does the field look like? Well, if you use one blunt measure — Charlie Cook’s House race reports — it looks a lot more like landslide than anti-incumbency. He’s got 35 currently Democratic seats that are either toss-up or better for the GOP. He’s got 3 currently GOP seats that are either toss-up or better for the Dems.

And this brings me to what is slowly becoming my central thesis of the week: anti-incumbency is only going to truly manifest itself when you bi-partisan support for unwanted policy (like 1854) or bi-partisan blame for corruption (like 1992). Anything else, and it’s way more likely that the aggregate electorate is just going to punish the governing party (like 1890 or 1930 or 1994). Yeah, people in both parties think Bush-style Republicans are crazy, but they’re going to hold their noses and vote for them in November.

I also think it’s interesting that people are getting all in a twist about what is probably going to amount to less than a 40 seat partisan turnover. While it’s true that gerrymandering might be tempering things, people are talking like this is political armageddon in November. But it would be shocking if it’s bigger than 1994. And no one is talking about anything approaching the mega-landslides (like 1890) or anti-incumbency tornado in 1854.

I should also say that 1854 bears a second look, because that’s a true anti-incumbency result: going into the election, the partisan breakdown in the House is approximately 150 Dems and 75 Whigs. When Congress reconvened after the election, the breakdown was 84 Democrats,  60 Whigs, 62 American Party (“know-nothings”), and 46 Republicans. I can’t see how that will ever be topped — the majority party loses almost half its seats, the minority party loses a fifth of its seats, and they all got to a minor party that previously held no seats and a new party that didn’t exist a year earlier!

Part of me thinks that the anti-incumbency meme is Democrats clinging to any hope that this isn’t a bloodbath for them in November. Part of me thinks its a media-generated netural storyline. But mostly, I think it’s people accepting a conclusion that makes sense on the surface, without really digging into the claim.