After a day that contained some scary polling for incumbent Democrats, today’s indicators were more equivocal.
Republicans strengthened their position in a couple of districts that received fresh polling from The Hill. In particular, John Spratt, the longtime Democratic incumbent in South Carolina’s 5th congressional district, was shown 10 points behind the Republican, Mick Mulvaney. Because the district had not received polling in some time, the poll has a lot of influence on Mr. Spratt’s forecast. The model now gives him just a 12 percent chance of holding his seat, a sharp decline from 53 percent yesterday.
The chances for two other Democrats, John Salazar in the Colorado 3rd district, and Baron Hill in the Indiana 9th, also dropped on The Hill’s polling.
But the same set of polls contained good news for other Democrats whom it tested, like Leonard Boswell in the Iowa 3rd district, and the two Democratic incumbents in the Dakotas, Earl Pomeroy and Stephanie Herseth-Sandlin, although both Mr. Pomeroy and Ms. Herseth-Sandlin are still rated as underdogs in the model.
Another Democrat to see her odds improve today was Colleen Hanabusa in the Hawaii 1st district, who was given a 5-point lead in a new poll that ordinarily has a strong Republican lean. Ms. Hanabusa is one of two Democrats favored to knock off a Republican incumbent, along with Cedric Richmond of the Lousiana 2nd district in New Orleans.
The Democrats’ position on the generic ballot also improved slightly, particularly with a Marist College poll showing them in an overall tie with Republicans among likely voters, a better result than most other recent polls.
But this improvement was offset by a series of downgrades made by CQ Politics, which changed its ratings in a couple dozen races, almost all of the changes favoring Republicans. The model gives a heavy emphasis to the race ratings issued by CQ and the three other agencies that it tracks.
Overall, the model resolved these changes in favor of Republicans, who added one more seat to their projected total for the second evening in a row. The model’s best guess is that the new Congress will be composed of 203 Democrats and 232 Republicans: a net gain of 53 seats for the G.O.P.
In addition, Democratic odds of retaining the House dropped to 17 percent from 20 percent; their chances of doing so essentially boil down to there being systemic errors in the polling and the other indicators that the model uses, as it is likely too late for them to alter the fundamentals of the electoral landscape.