MT-1 · House

The district, in brief

Montana's 1st district is based in western Montana, including Missoula, Bozeman, Butte and Kalispell. The lines are the map first used in 2022 and the district is not redrawn for 2026. The facts give a 2024 presidential baseline on these lines of -11.9 for the Democrat on the two-party vote.

The seat is open. The incumbent, Republican Ryan Zinke, was re-elected with 52.3% of the vote in 2024 (a two-party margin of -7.92 for the Democrat in the facts) and on March 2, 2026 announced he would retire at the end of his term; he withdrew from the primary and endorsed Aaron Flint. Flint, a combat veteran and radio host, won the Republican primary with 50.1% against Secretary of State Christi Jacobsen (23.0%), former state senator Al Olszewski (20.3%) and Ray Curtis (6.7%). The Democratic nominee is Sam Forstag, a smokejumper and union leader, who won his primary with 37.3% against 2024 gubernatorial nominee Ryan Busse (33.1%), Russell Cleveland (21.7%) and Matt Rains (7.9%); former governor Brian Schweitzer endorsed Busse, then Forstag. A Libertarian, Nick Sheedy, and an independent, Kimberly Persico, are also on the general-election table. As of June 30, 2026 Flint had raised $1,303,394 with $502,201 on hand; Forstag $1,382,873 with $550,079 on hand.

Every rater listed calls the seat R: Decision Desk HQ (July 14, 2026), the Cook Political Report (September 25, 2026), Inside Elections (March 12, 2026) and Sabato's Crystal Ball (September 29, 2026). The text records five general-election polls: American Pulse for NonStop Local (September 19–24, 2026, 314 LV) Flint 46%, Forstag 45%, Sheedy 5%; Public Policy Polling, a Democratic firm (September 9–10, 2026, 536 RV) Forstag 45%, Flint 43%; Rutgers Eagleton (August 27 – September 7, 2026, 375 RV) Flint 42%, Forstag 41%, Sheedy 5%; Impact Research for Forstag's campaign (June 22–25, 2026, 500 LV) 44% each, Sheedy 5%; and Upswing Research for 314 Action (April 30 – May 5, 2026, 401 LV) Flint 48%, Forstag 43%.

A paragraph quoting a model forecast from the day this brief was written is omitted; the current forecast is at the top of this page.

The facts, each beside its sentence

Not in the source: The model's basis says no district polls, but the text records five general-election polls (plus primary and hypothetical matchups); they are not in the project's poll corpus.; The text gives no 2024 presidential result in prose; the only presidential figure is the facts' two-party baseline.; No rating finer than 'R' is given (no Lean/Likely/Safe).; The endorsements sections in the text are empty apart from the Zinke and Schweitzer notes; the text gives no description of Nick Sheedy or Kimberly Persico.; The text spells the Republican runner-up both Jacobsen and Jacobson.

Read from the district's section of Wikipedia's state page (CC BY-SA), archived as efa5281b33be; written by claude-fable-5-1 (batch reader) on 2026-09-30 and checked mechanically: every quote occurs verbatim in the archived text, every number in the brief occurs in the inputs. No probability here is the reader's.

Who holds the seat now

Ryan K. Zinke (Republican), in this chamber since 2015, 4 terms. Committees: House Committee on Appropriations; House Committee on Foreign Affairs.

From the congress-legislators dataset (CC0), archived as ae8cb9477c48. For a Senate race this lists both of the state's senators; the one whose term ends in the election year holds the seat on the ballot. For a House district redrawn for 2026 it is the member elected under the old lines with this number, who may be running elsewhere; the dossier above names who is running here.

How it has voted for president

A shift of 0.9 points toward the Democrats from 2016 to 2024. county returns placed on the current lines by 2020 block population; MEDSL county file (2016), an MIT-licensed county file (2020, checked against certified state results) and MEDSL precinct returns (2024). For a district split across counties this is an estimate, and where the state published the exact 2024 figure for these lines, that exact figure is the one the model uses.

Who are the voters?

Of about 381,365 adults 25 and over. In 2020 the district voted 46.5% Democratic (two-party) for president. With the same preferences and a 2022-style midterm turnout, it would vote 47.4% Democratic: the midterm electorate alone moves the margin 2.0 points toward Democrats. Group shares are estimated from how results vary across the state's census tracts (ecological inference, anchored to Pew's 2020 validated-voter figures) and calibrated to this district's actual 2020 vote; turnout is the Census survey's state rate by race and national rate by education, whose state samples carry margins of several points.

Not answered here: how each group will vote in 2026. These are 2020 preferences; this profile is description, not yet an input to the forecast.

The money

FEC bulk candidate summaries through June 30, 2026; $1,541,907 of independent expenditures for or against these candidates this cycle (FEC Schedule E, types 24E and 24A), which is the parties' and outside groups' own revealed view of whether this seat is in play.

The district in numbers

ACS 5-year 2023, the Census Bureau's own tabulation of this district (118th Congress lines). Unemployment is the BLS county series placed on the district by block population, not seasonally adjusted, so changes are same-month comparisons. Income, transfers and jobs are BEA county accounts placed the same way, compared with the average district. Every other figure is a named column of a named table in the Bureau's summary file, archived before it was read. This is what a reader knows about a district before looking at a poll; the model does not yet use it, and whether it should is a registered question.

Who is favoured, and by how much?

The 90% interval runs from -15.2 to +14.6 points, D-R. It is wide because this district has never been polled.

What is this built on?

A model trained on every contested House race 2012-2024 predicts this district's lean from its own record: presidential and House results on the current lines, incumbency, both candidates' prior offices, outside and party money before 1 October, demographics and public-assistance shares from the Census release before the election, local unemployment and income, and religious tradition. The national margin comes from presidential approval, the economy, the midterm penalty and the generic ballot corrected for its measured lean. Draws share national and state errors, so the seat total and this district come from the same simulation.

Not answered here: district polls, which are not yet folded in.

Why does the model say this?

Each figure is how far this district's predicted lean moves when that one feature is set to the typical value across 2026 districts, everything else held: total outside/party money: 2.0 pts toward the Democrat; 2024 presidential lean (R+10.4): 1.8 pts toward the Republican; outside money balance: 1.6 pts toward the Democrat; black share (0.3%): 0.9 pts toward the Democrat; hispanic share (4.4%): 0.6 pts toward the Democrat.

How sure is it, and of what?

Total sd 9.11 points, made of the seat's own volatility 92%, correlated polling error 8%. The decomposition is stored with the forecast rather than reconstructed, so a probability whose dominant input is a placeholder is visibly that.

Not answered here: a nowcast. 'If ballots were cast today' needs something that observes today, and for a House district nothing does. Publishing the election-day figure under both labels would make one forecast look like two.

How was this number made?

Run 0b33151b-a949-47f1-b845-564833a2b74d, house_district_prior/0.2.0, as of 2026-10-02. Promoted by a pre-registered gate: on 2016-2022 its Brier score was 0.036 against 0.049 for the previous method, and on a single 2024 run 0.023 against 0.032 (experiments/district_gate_result.md, with an independent review).