Democrats favored for House, Senate near a coin flip 78 days out

Our model, updated August 16 at 11:27 PM ET, gives Democrats a 93 in 100 chance of winning a House majority, with a mean of 242.2 seats against the 218 needed for control. Republicans are at 7 percent. One note on how that figure is built: our simulation draws correlated error nationally, by census division, by state and by district, but it carries no demographic-cluster term because we have no cluster data. That makes the House control probability marginally firmer than a fuller decomposition would produce.

The Senate is closer. Our model gives Democrats a 46 percent chance of a majority and Republicans 54 percent, with a mean of 50.1 Democratic seats. Democrats need 51 seats for control; Republicans need 50, because the vice president is a Republican and a 50-50 tie goes to their side. The mean sits between those thresholds, which is why the chamber prices near even.

Our generic ballot average stands at D+6.7, drawn from 26 polls fielded in the last 45 days.

Recent state polling is mixed. In Michigan, two surveys with overlapping field dates disagree: Beacon Research/Shaw & Co. Research, polling 1,006 registered voters August 6-10, had Republican Mike Rogers at 51 percent and Democrat Abdul El-Sayed at 47; GBAO, polling 800 likely voters over the same dates, had El-Sayed at 50 and Rogers at 44. In Ohio, both recent polls favor Democrat Sherrod Brown over Republican Jon Husted: Wedgewood Polls, 800 likely voters August 11-13, had it 48-44, and Beacon/Shaw, 1,008 registered voters August 6-10, had it 53-45. Harper Polling, surveying 600 North Carolina likely voters August 9-10, had Democrat Roy Cooper at 52 percent and Republican Michael Whatley at 39.

Several other Senate contests polled close. Emerson College, with 1,000 Texas likely voters August 9-10, had Republican Ken Paxton at 47 and Democrat James Talarico at 46. Public Policy Polling, with 569 Kansas likely voters August 7-8, had Republican Roger Marshall at 46 and Democrat Adam Hamilton at 45. Beacon/Shaw, with 1,000 Maine registered voters August 6-10, had Democrat Troy Jackson at 48 and Republican Susan Collins at 46. The Bullfinch Group, polling 608 Idaho likely voters on August 13, had Republican Jim Risch at 34 percent and independent Todd Achilles at 30. In House districts, Bedrock Polling had the Democrat ahead of the Republican 43-35 in OH-7 among 866 likely voters August 7-10; SurveyUSA had the Democrat at 43, the Republican at 39 and other candidates at 5 in NY-21 among 612 likely voters August 4-8; and Impact Research had WI-1 at 49-48 for the Republican among 400 likely voters August 6-9, a close result.