Senate control stays close in our model as Texas and Florida odds move toward Republicans

With 39 days to the November 3 election, our model gives Democrats a 55 in 100 chance of winning Senate control and Republicans a 44% chance, as of 6:32 AM ET on September 25. Democrats need 51 seats for a majority. Republicans need 50, because the vice president is a Republican and a 50-50 tie goes to them. Our model's mean outcome is 50.8 Democratic seats, just short of that line.

The House picture is less close. Our model gives Democrats a 98% chance of winning control and Republicans 2%, with a mean of 245.7 Democratic seats against the 218 needed. Our simulation correlates polling error nationally, by census division, by state and by district. It does not yet correlate demographically similar districts in different places, because we lack the cluster data to do so. That makes our House control probability somewhat firmer than it would be with that term included. Our generic ballot average stands at D+8.3, drawn from 29 polls over a 45-day window. An Emerson College survey of 1,000 likely voters, fielded September 21-22, had Democrats at 53.2% and Republicans at 41.9%. A McLaughlin & Associates survey of 1,000 likely voters, fielded September 16-22, had Democrats at 48% and Republicans at 43%.

Several Senate races moved in our model. Our Democratic win probability in Kansas is now 37%, up from 9%. Iowa rose from 43% to 60%, and Minnesota from 71% to 87%. Michigan rose from 66% to 72%. Two races moved the other way: Texas fell from 70% to 54%, and Florida from 29% to 18%.

In Michigan, recent polls diverge. A New York Times/Siena University survey of 605 likely voters, fielded September 15-22, had Abdul El-Sayed at 49.45% and Mike Rogers at 44.5%. A co/efficient survey of 843 likely voters, fielded September 21-23, found the race tied at 45% each, and at 50% each when respondents were pressed to choose. In Ohio, a Quantus Insights survey of 695 likely voters, fielded September 21-23, found a close race: Sherrod Brown at 47.3% and Jon Husted at 46.8%, and 47.6% to 47.2% in a head-to-head version.

Elsewhere, a New York Times/Siena University survey of 619 likely voters in Maine, fielded September 15-22 for the Portland Press Herald, found a close race, with Susan Collins at 48.66% and Troy Jackson at 45.92%. The same pollster's New Hampshire survey of 613 likely voters, fielded over the same dates, had Chris Pappas at 49.82% and the Republican at 44.82%. In North Carolina, a Quantus Insights survey of 686 likely voters, fielded September 21-22, had Roy Cooper at 48.4% and Michael Whatley at 43.3%.