Normally, I use this space to run down various news items related to the campaign, but today I am going to deviate from that practice to offer a snapshot of where I think the midterm battle stands.
The place to start is with independent voters, as they are the ones who swing elections in contemporary America. Indeed, as the parties have become more polarized, independents are now more important politically than ever before. The following is an average of the independent vote in the generic ballot polls in the RealClearPolitics average:
This is a major problem for the Democratic party. It is averaging less than one out of three independent/unaffiliated voters. Importantly, all of these polls indicate that party voters have generally sorted themselves out – Republican voters have already broken to Republicans, Democrats to Democrats. Most of the undecided voters at this point are independents.
It’s hard to say how the remaining independents will finally break, though I think the best case scenario for the Democrats is that they break evenly between the two parties. The worst case would be if they break 9:1 or thereabouts for the Republicans. My guess is that the remaining independents break roughly as the decided ones have broken, on about a 4:3 basis toward the GOP.
This would create a result among independent voters that is basically indistinguishable from 1994 – about 56 percent to the Republicans, 40 percent to the Democrats, and a smattering to third-party candidates. By the way, this is also about the inverse of how independents broke in 2006. What's more, Gallup has generally found President Obama's job approval with independents around 40 percent, so it stands to reason that this is how well the Democrats will do with independents next month.
But where will the final results stand? The polls are all over the place – Newsweek says the Dems have a 5 percent lead, while CNN says the GOP is running away with it. These differences are not really due to variations in the independent vote, which as you can see above is pretty stable across polls. It is mostly due to variations in the relative strength of both parties in any given sample – how many Republicans are in the sample, how many Democrats, and how well both sides perform with their partisans.
This is where polls this cycle can really lead us astray. In particular, that Newsweek poll, which finds the GOP down 5 overall but up 17 with independents, should raise some alarms. The only way to square a D+5 national result with an R+17 independent result is to predict a heavily Democratic electorate, which is exactly what Newsweek did. But in reality the partisan composition of the midterm electorate has been quite stable for the last four midterms, with both sides being roughly equally proportioned.
Of course, small changes in the partisan composition of the electorate could have a big impact on the House. While the independent vote has been pretty stable for some time, Democrats are working furiously to drive up enthusiasm among their own partisans. What kind of result could their efforts produce, if we assume that independents remain unchanged?
To get an answer to this question, let’s map out a couple scenarios for the final 2010 House result and assume that the independents break like they did in 1994 – 56 percent Republican to 40 percent Democratic.