New MT-1 poll shows a close race; our forecast nudges to 57 in 100

A Public Policy Polling survey of 536 registered voters in Montana's 1st District, sponsored by The Bench and fielded September 9-10, put Democrat Sam Forstag at 45 percent and Republican Aaron Flint at 43 percent. A two-point gap on a sample that size does not establish a leader. The poll describes a close race.

Our model gives Forstag a 57 in 100 chance of winning the seat, against 43 percent for Flint. That is up from 56 percent in our previous run, at 8:32 AM ET on September 16. The mean margin moved from D+1.3 to D+1.6, and the 5th-to-95th percentile range shifted from R+13.8-to-D+16.5 to R+13.5-to-D+16.8. In other words, the new number confirmed what was already in the average rather than changing it. Our published reaction on September 15 noted that a tied poll had trimmed the Democrat's edge; this survey moves it back by about a point. Neither shift is large relative to the spread our model still carries in this district, which spans double-digit outcomes in both directions. A third candidate, Nick Sheedy, is on our list for the race and was not tested in the poll.

Nationally, our average of 25 generic-ballot polls over the past 45 days stands at D+7.2. Our model gives Democrats a 96 percent chance of winning House control, with a mean of 242.3 seats against the 218 needed. One caveat is ours to own: our simulation draws correlated error at the national, census-division, state and district levels, but it has no term linking demographically similar districts in different places, because we have no cluster data for it. That makes the House control probability marginally firmer than a fuller model would report. In the Senate, our model gives Democrats a 51 percent chance of control.