The latest FiveThirtyEight projection for the House of Representatives shows little overall change from our previous update, released this weekend, but the Republican position has improved slightly. They are now given a 75 percent chance of winning the House on Nov. 2, up from 73 percent previously. During an average simulation run, the Republicans finished with a total of 228 seats (up from 227): this would reflect a net gain of 49 seats from their current position.
As I have warned repeatedly in the past, we believe that the uncertainty in the forecast is intrinsically quite high, stemming from the unusually large number of seats in play, and from differences of opinion among pollsters in how to calibrate their likely voter models to account for the so-called “enthusiasm gap.” There are only 170 seats that the model thinks of as “safe” Republican — those where their chances of winning are 95 percent or higher. However, there are only 151 seats that the Democrats are at least 95 percent assured of winning.
The slight movement toward Republicans this week is not the result of shifts in the polling. Our estimate of the generic ballot remains unchanged, showing about 6 point lead for Republicans among likely voters. And some of the local polling has been decent enough for Democrats in the past few days, like a nonpartisan survey showing their incumbents ahead in two tight races in Michigan, and a poll suggesting that Ben Quayle, a Republican, could lose in Arizona’s 3rd Congressional District — although our model is skeptical and still gives Mr. Quayle an 89 percent chance of prevailing.
Some polls can also be prone to misinterpretation by those who lose sight of their context. The large batch of polls released by The Hill this week shows many Democratic sophomores trailing. Clearly, this is not good news for Democrats — but in most cases, these sophomores are in difficult districts and had already appeared likely to lose in a universe in which Republicans were poised to gain 50 or so seats.
But there are other indicators that have unambiguously broken Republicans’ way this week. Third-quarter fundraising reports trickled in over the weekend, and Republicans bettered Democrats there — and not just because of contributions from outside groups that some Democrats have been complaining about. Instead, aggregate individual contributions for candidates who will appear on the House ballot in November totaled $74.3 million for Republicans, versus $54.3 million for Democrats. Although Democratic candidates generally had the stronger fundraising numbers early in the cycle, and in some cases have more money in the bank, this is nevertheless an auspicious figure for Republicans, particularly since they have fewer incumbents and fundraising can be a more cumbersome task for challengers.
Meanwhile, Cook Political again downgraded their rating for Democrats in a number of key seats. Dramatically, for instance, they now regard Raul M. Grijalva’s race in Arizona’s 7th Congressional District as being a tossup; whereas they had scored the race as safely Democratic mere weeks ago. (Our model now thinks that Mr. Grijalva has a 21 percent chance of losing his seat.)
For the time being, we are still in a universe where Democrats could probably hold the House by having the coin come up heads in a sufficient number of tossup races.
We may not be far from the point, however, where their chances would boil down, in essence, to there being systemic errors in the polls, which could potentially affect a large number of races — or there being some sort of last-minute change in the macro environment.