November 6, 2018


Our Final Forecast In The Senate, House And Gubernatorial Races (Nathaniel Rakich, 11/06/18, 538)

Republicans have a 5 in 6 chance (82.0 percent) of holding on to the Senate in the Deluxe version of our forecast (which we'll be using as the default version of the forecast for Election Day). In other words, Republicans are a strong, but not insurmountable, favorite in the upper chamber. Any scenario from a three-seat Republican gain to a two-seat Democratic gain falls within our 80-percent confidence interval. [...]

Democrats have a slightly better chance of winning the House than Republicans do of holding the Senate. Democrats are a 6 in 7 favorite (85.8 percent) to win a majority of seats. Their average seat gain is 36, which would result in a House of Representatives with 231 Democrats and 204 Republicans. But the model considers a wide range of outcomes as still well within the realm of possibility: We think there's an 80 percent chance that Democrats gain somewhere between 20 and 54 seats.

Roughly, your expectation should be that a Republican upset in the House is about as unlikely as a Democratic upset in the Senate. However, it's much less likely that we will see an upset in both chambers at once, because polling errors tend to lean in the same direction, so if Democrats perform better than expected in the Senate, they will probably also perform better than expected in the House. [...]

Finally, our model foresees that Democratic governors will preside over an average of 24.2 states in 2019, or eight more than the party's current 16. That would mean that roughly 197 million Americans, or 64.4 percent of the country's population, would have a Democratic governor.

Posted by at November 6, 2018 5:19 PM