Senate sits at even odds as our House estimate holds at 96 in 100

Forty-nine days out, our model splits the Senate almost exactly down the middle: a 50% chance Democrats win control, 49% for Republicans, with a mean of 50.3 Democratic seats as of 6:32 AM ET. The thresholds are asymmetric. 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. That gap is why a model centered just above 50 seats produces something close to a coin flip.

The House is not close on our numbers. Our model gives Democrats a 96 in 100 chance of winning a majority there, against 4% for Republicans, with a mean of 241.8 seats and 218 needed for control. One caveat belongs on that figure: our simulation draws correlated error at the national, census-division, state and district levels, but not across demographically similar districts in different places, because we have no cluster data for it. The missing term would loosen the distribution somewhat. We have not measured by how much, so we are not putting a number on it.

The generic ballot average stands at D+7.0, drawn from 24 polls over the past 45 days. Recent surveys straddle it. A YouGov poll for CBS News of 1,750 likely voters, fielded September 8-11, had Democrats at 54% and Republicans at 46%. The New York Times/Siena University put Democrats at 51.28% and Republicans at 42.76% among 1,503 likely voters fielded September 8-13, and at 49.01% to 42.18% among the same registered-voter sample. An Ipsos survey for Reuters of 896 registered voters, fielded September 11-14, had it 44% to 37%. Morning Consult, polling 30,013 registered voters September 7-13, had the narrowest split of the four at 46.3% to 42.4%.

The largest movement over the past day came in Maine, where our estimate of the Democratic chance fell 18.2 points to 72%, and in Iowa, where it rose 12.7 points to 45%. Ohio also moved, settling at a 60% Democratic chance, and North Carolina rose 8.2 points to 84%. South Carolina moved from 6% to 14%, still the longest of the six. Texas gained 7.7 points to 70%.

Three state polls landed alongside those shifts. SoCal Strategies had James Talarico at 50% and Ken Paxton at 45% in Texas among 649 likely voters fielded September 12-13. The Trafalgar Group put Jon Ossoff at 49.4% and Mike Collins at 42.8% in Georgia, with 1.3% for an independent, among 1,091 likely voters fielded September 10-12. Trafalgar also had Roy Cooper at 48.2% and Michael Whatley at 42.3% in North Carolina among 1,084 likely voters fielded September 8-10.