Senate at 42-57, House at 94-6, generic ballot average at D+6.3

Fifty-four days out, our model gives Democrats a 42 in 100 chance of winning Senate control and Republicans a 57 percent chance. The mean Democratic Senate seat count in our simulations is 49.8. 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. In the House, our model puts the Democratic chance of a majority at 94 percent and the Republican chance at 6 percent, with a mean of 239.4 Democratic seats against the 218 needed for control. All figures are as of 6:32 AM ET on September 10.

One caveat on the House number is ours to make. Our simulation draws correlated error at four levels: nationally, by census division, by state, and within each district. It does not include a term linking demographically similar districts in different places, because we have no cluster data for one. The effect is that our House control probability is marginally firmer than a fuller error model would make it. We have not measured how much, so we are not putting a number on it.

Our generic ballot average stands at D+6.3, built from 24 polls over the past 45 days. The most recent additions run wider than that. A YouGov survey for The Economist, fielded September 4-8, had Democrats at 49 percent and Republicans at 38 among 1,015 likely voters, and 42 to 35 among 1,464 registered voters. Focaldata, polling for the Financial Times from August 28 to September 2, had it 48.7 to 42.3 among 1,914 registered voters and 46.3 to 40.6 among 2,180 adults. Morning Consult, fielded August 31 to September 6 with 29,427 registered voters, was closer: Democrats 46.3, Republicans 42.2.

The largest moves in our estimates were toward the Republicans. Ohio Senate fell 11.5 points of Democratic win probability, from 49 percent to 37 percent, and Kansas Senate fell 9.7 points, from 14 percent to 4 percent. Iowa Senate dropped 6.6 points to 31 percent. Maine Senate eased another 4 points to 83 percent for the Democrat. In the other direction, Texas Senate rose 4.9 points to 69 percent and CA-48 rose 6.7 points to 22 percent.

Elsewhere in the polling, TIPP Insights, sponsored by the League of American Workers and fielded August 31 to September 2, found the Minnesota Senate race close: 44.0 percent Democratic to 41.9 percent Republican among 1,192 likely voters, with independent and other candidates at 4 percent combined. Glengariff Group, for The Detroit News and WDIV-TV, had Michigan close on August 31 to September 3, with Mike Rogers at 45.8 percent and Abdul El-Sayed at 44.4 among 600 likely voters. In NY-21, Impact Research put Anthony Constantino at 47 percent and Blake Gendebien at 44 among 500 likely voters, fielded August 30 to September 2 — also close.