A point I’ve been wanting to make about the coming midterm elections is that a lot of commentators seem to me to be operating with a misleading implicit model of how these things work. The way they see it, the status quo in any given pre-election House is a kind of equilibrium, and moving the House off that equilibrium requires force. Since the Democrats currently have a large majority, it follows that to move from a large Democratic majority to parity would require an enormous amount of force. Thus, if the GOP is close to taking control of the House is follows that the “political climate” is very bad for Democrats—the GOP is succeeding in applying a lot of force.
This, I think, miscasts how House elections work. The stable equilibrium point should be near-parity. Indeed, thanks to the vagaries of congressional districting (Democrats are more likely to be “packed” into massively uncompetitive inner-city districts), the stable equilibrium is a small GOP advantage. Because the whole House turns over every two years, to merely sustain a large Democratic majority requires an overwhelmingly favorable political climate. Since Democrats clearly don’t have such a climate, they’re facing massive losses. But “massive losses” will make the House close to even, reflecting a closely split American public.
Alan Abramowitz’s election forecast model backs this up:
Contrary to many other analyses, however, the results of the forecasting model indicate that the main factors contributing to likely Republican gains in November are structural and do not reflect an especially negative political environment for Democrats. The current political environment only appears unfavorable for Democrats compared with the extraordinarily favorable environment that the Party enjoyed in both 2006 and 2008. The two structural variables in the model—previous Republican seats and the midterm dummy variable—predict a Republican gain of 38 seats, half due to the small number of Republican seats prior to the election and half due to the fact that 2010 is a Democratic midterm year. According to this model, the main reasons that Democrats are likely to experience significant losses in 2010 are the normal tendency of voters to turn against the president’s party in midterm elections regardless of the national political environment and the fact that after gaining more than 50 seats in the past two elections, they are defending a large number of seats, many in Republican-leaning districts.
Based on the latest readings on net presidential approval (approximately +5) and the generic ballot (tied), the national political environment is fairly neutral at the moment. Even under what might be considered a best-case scenario for Democrats, if President Obama’s net approval rating were to improve from a +5 to a +20, and Democrats were to regain a 10 point lead on the generic ballot, Democrats would still be expected to lose about 20 seats in the House.
This is important, because given that people don’t understand it a situation in which Democrats go from a very large majority to a slim majority is likely to be spun as a massively repudiation of the congressional leadership’s approach. The reality, however, is that were Democrats to be massively repudiated the result would be a very large GOP majority.