Final Polling Suggests a 50+ Seat Pickup for GOP in the House
According to the Gallup poll released Sunday, the Republicans have a 15-point lead among likely voters. NBC/ Wall Street Journal has them up by 6. CNN/Opinion Research shows the GOP with a ten-point lead. Pew has a 6-point spread, and the ABC/ Washington Post poll shows the Republicans leading by 4 (all via PollingReport).
How does this all translate into House seats? Super-number-cruncher Nate Silver lays it out like this:
Political scientists have formulas to translate the results of the generic ballot to an estimate of the number of seats that the Republicans will gain. I’m not much of a fan of these formulas for a number of reasons, but let’s see what they say.
The most widely-used formula says that a Republican advantage of 7 points among likely voters on the generic ballot — which is about what the average is — would translate to a Republican gain of 53 seats. But if you plug the Gallup likely voter results into the model instead (the model was originally designed around Gallup data, in fact), it projects a G.O.P. gain of 77 seats. If you use the Newsweek poll, on the other hand, it shows Republicans gaining just 23 seats.
Our model is a lot more sophisticated than that. It does look at the generic ballot, but it doesn’t necessarily assume that it is right. It also looks at local polls in each congressional district, expert ratings, fundraising data — the whole kit and caboodle. Unlike the political science models, it formulates an estimate of the result in each individual congressional district, and not just the overall seat count.
But it tells you basically the same thing. Tonight, our forecast shows Republicans gaining 53 seats — the same as in recent days, and exactly the same answer you get if you plug the generic ballot average into the simple formula. Our model also thinks the spread of potential outcomes is exceptionally wide: its 95 percent confidence interval runs from a 23-seat Republican gain to an 81-seat one.
In the Senate, models predict a Republican pickup of 7-8 seats.