Tuesday, October 26, 2010

Nate Silver: '52-Seat Gain For G.O.P.'

Sounds about right:
If Democrats were hoping for a late surge to improve their chances of retaining control of the House, there isn’t any evidence of it yet. Instead, Republicans have generally had the better of the polls in individual House districts released in the past 24 hours.

FiveThirtyEight’s forecast now projects the most likely composition of the House to be 231 Republicans and 204 Democrats. This is a one-seat improvement for the Republicans from yesterday’s forecast, and would mean that they’d gain a net of 52 seats over all.

There is uncertainty in the forecast: Democrats have a 20 percent chance of maintaining control of the House, essentially unchanged from a 21 percent chance yesterday. Much of this 20 percent probability reflects the potential for there to be systematic errors in the polling, as there were in years like 1998.

Since there are a very large number of competitive seats, relatively small anomalies in the polling could potentially affect the outcome of dozens of races. Although the Democrats’ overall position is poor, it is not yet so poor that it couldn’t be salvaged if they beat their polling averages by 2 or 3 points nationwide.

Still, such errors could also work in Republicans’ favor, potentially enabling gains in excess of 60 or even 70 seats....