FiveThirtyEight’s House projection is unchanged over the past 48 hours. Over the course of its simulation runs, our model found Republicans gaining an average of 53 seats, which would bring them to 232 total. Democrats are given a 16 percent chance of holding the House, down slightly from 17 percent on Wednesday.
Increasingly, there seems to be something of a consensus among various forecasting methods around a projected Republican figure somewhere in the 50-60 seat range.
Several of the expert forecasters that FiveThirtyEight’s model uses, like the Cook Political Report, the Rothenberg Political Report, and Larry Sabato, have stated that they expect the Republicans’ overall total to fall roughly in this range. A straw poll of political insiders for Hotline on Call found an average expectation of a 50-seat gain. And some political science models have been forecasting gains somewhere in this range for some time.
The forecast also seems consistent with the average of generic ballot polling. Our model projects that Republicans will win the average Congressional district by between 3 and 4 points. In recent years — because turnout is generally heavier in Republican districts — the aggregate House popular vote has been 3 to 4 points more Republican than the result in the vote in the average district. Thus, our model seems to imply that Republicans will win the House popular vote by 6 to 8 points, which is roughly consistent with current averages of generic ballot polls. (Our averaging method currently has Republicans ahead by 6.1 points on the generic ballot).
Polls of individual districts, as always, are more mixed. But, there are no lack of juicy data points for Republicans to support a gain of 50-60 seats — or perhaps at least a dozen more. New polling in Rhode Island, for instance, shows the Republican John Laughlin with a decent chance to pick up that state’s First Congressional District, while another new poll shows Republicans nearly tied with Democrats in each of Maine’s two Congressional districts. One should probably be cautious about reading too much into polling in these two particular states, since they may be affected by the unusual dynamics of each state’s three-way gubernatorial races, each of which are turning against the Democrats. Nevertheless, Republicans have no lack of targets to reach 50 or 55 seats, and are roughly as likely to pick up 70 or more seats as Democrats are to hold the House.
With that said, the fact that there is a seeming consensus does not necessarily indicate that it will be right. However objective or subjective a forecasting method, all are pretty much looking at the same data, and 90 percent of that data amounts to polling. This is also the time of year when everyone tends to look at everyone else’s forecasts (our model does so explicitly, in fact, since the forecasts made by experts like Cook are an input in the model), which may reduce independence. If the polling is off — and it could be off in either direction — the consensus is liable to be too. Still, this is not the position that Democrats might have hoped to find themselves heading into the final week of the campaign.