A tied MT-1 poll trims the Democrat's edge in our forecast

A Rutgers-Eagleton survey of 375 registered voters in Montana's 1st District, sponsored by Montana Free Press and fielded August 27 to September 7, found Republican Aaron Flint at 42 percent and Democrat Sam Forstag at 41 percent, with 5 percent for other candidates. On a sample that small, a one-point gap is not a lead. The poll describes a close race.

Our model gives Forstag a 55 in 100 chance of winning the seat, down from 58 percent in our previous run earlier today. The mean margin in our simulations is D+1.2, narrowed from D+1.9. The spread is wide: our 5th-to-95th percentile range runs from R+14.0 to D+16.4, which is to say we can rank the two candidates but not the size of the outcome.

That is a small move, and it is the kind of move a single small-sample poll should produce. Nothing in the new number contradicts what the forecast already said about MT-1, which is that the district is close to even and slightly tilted toward the Democrat.

Nationally, our average on the generic ballot is D+6.8 across 24 polls in a 45-day window. Our model gives Democrats a 95 percent chance of reaching the 218 seats needed for House control, with a mean of 240.9 seats. One caveat on that figure is ours to own: our simulation correlates error nationally, by census division, by state and within each district, but we have no cluster data to correlate demographically similar districts across state lines. Without that term, our House control probability is somewhat firmer than a fuller model would make it.