House at 97 percent in our model, Senate at 52-48 with 43 days left

Forty-three days from the November 3 election, our model gives Democrats a 52 percent chance of winning Senate control and Republicans 48 percent, with a mean of 50.4 Democratic seats. Democrats need 51 seats for a majority and Republicans 50, because the vice president is a Republican and a 50-50 tie goes to the Republicans. In the House, our model gives Democrats a 97 in 100 chance of winning a majority, with a mean of 242.5 seats against the 218 needed.

Our generic ballot average, as of 6:32 a.m. ET on September 21, stands at D+7.3, drawn from 29 polls fielded over the past 45 days. Two of the newer entries are close to that mark. John Zogby Strategies, surveying 1,007 likely voters September 15-17, put Democrats at 48 percent and Republicans at 42. Morning Consult, for the CATO Institute, surveyed 4,150 registered voters September 13-16 and found Democrats at 47 percent and Republicans at 42.

The largest movement in our Senate estimates since yesterday came in North Carolina, where the Democratic win probability rose 9.6 points to 93 percent. An InsiderAdvantage survey of 1,200 likely voters, fielded September 16-17, had Roy Cooper at 48.4 percent and Michael Whatley at 42.5 percent, with 1.6 percent for other candidates. Florida moved 6.7 points toward the Democrats, to 35 percent, after St. Pete Polls, sponsored by Florida Politics, surveyed 913 likely voters September 15-17 and found Ashley Moody at 45.2 percent and the Democrat at 44.8 percent — a difference too small to separate the candidates. Michigan moved 4.3 points the other way, to 66 percent, on an InsiderAdvantage poll of 1,200 likely voters, September 16-17, that had Abdul El-Sayed at 46.6 percent and Mike Rogers at 44.7 percent, also close.

Elsewhere, Emerson College, for The Hill, surveyed 750 Kansas likely voters September 15-16 and found Adam Hamilton at 44.8 percent and Roger Marshall at 43.3 percent, with 3.7 percent for others; our Kansas estimate is 19 percent for the Democrat, up 10.6 points. In New Hampshire, InsiderAdvantage's poll of 1,200 likely voters, September 16-18, had Chris Pappas at 48 percent and the Republican at 40. In Alaska, co/efficient surveyed 799 likely voters September 14-17 and found Dan Sullivan at 49 percent and Mary Peltola at 46. Iowa moved 4 points toward the Republicans, to 42 percent for the Democrat.

One note on the House figure. Our simulation draws error at four correlated 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 it. That omission makes the 97 percent slightly firmer than a fuller model would produce; we are not measuring how much this run, so we are not putting a number on it.