Scan: Will the Republicans win the Montana Senate race in 2026?

date	predicted	market price	confidence
2026-08-31	91%	92%	75%
2026-08-17	94%	92%	67%

1. Planner Fable 5.1 · Fermi decomposition + tool plan

Tools chosen: polymarket_direct kalshi_related polymarket_related article_search claude_news wikipedia code_execution

Sub-questions (Fermi decomposition)

Is incumbent Republican Sen. Steve Daines running for re-election in 2026, and has any credible primary challenger emerged?
Who is the Democratic nominee or leading Democratic candidate in the 2026 Montana Senate race, and what is their fundraising and name recognition?
What do recent polls (2025-2026) show for the Montana Senate race, and what are ratings from Cook, Sabato, and Inside Elections?
What is the national generic ballot / midterm environment for Republicans, and how much could it shift a Trump+20 state?
Is there a significant independent or third-party candidate (e.g., Libertarian or an independent with Democratic ties) who could affect the outcome or the 'Republican' resolution?
What is the historical base rate of incumbent senators from the president's party winning re-election in states the president won by 15+ points during midterms?
How do Kalshi and Polymarket prices compare on this race and on Senate control overall?

Planner reasoning

This is a Polymarket question about the 2026 Montana Senate race, where incumbent Republican Steve Daines is heavily favored in a state Trump won by ~20 points. The key uncertainties are whether Daines runs (or retires, opening a primary), who the Democratic nominee is and their fundraising/polling, the national environment for Republicans in a midterm, and any third-party/independent dynamics (as with Tester's races). Market price is the primary anchor; cross-venue Kalshi prices and recent news on candidate announcements and polling are the main updates.

2. Research Parallel tool calls

tool	status	time	items	summary
polymarket_direct	OK	0.7s	1	## This Market's Polymarket Data Will the Republicans win the Montana Senate race in 2026? - Current price (probability): 92.50% - 7-day price change: +1.50% - 30-day price change: +0.00% - Total volume: $65,180 (USD notional) - Price range: 76.50% - 93.00% - Data points: 91 days
kalshi_related	OK	3.2s	2	2 related markets / summaries. keyword 'Montana Senate': ok \| keyword 'Daines': no matches \| keyword 'Senate control 2026': ok
polymarket_related	OK	0.4s	15	Polymarket search over 3 keyword(s), kept 15 matches. keyword 'Montana Senate': 5 markets \| keyword 'Daines': 5 markets \| keyword 'Senate control': 5 markets
article_search	OK	0.7s	13	Fetched 13 unique articles across 3 queries (lookback=90d). 'Montana Senate race 2026 Daines': 10 articles \| 'Montana Senate Democratic candidate 2026': 10 articles \| 'Montana Senate poll 2026': 10 articles
claude_news	OK	31.0s	24	Based on research into the 2026 Montana U.S. Senate race: - Daines is retiring, not running for re-election. At 4:52 PM on March 4, 2026, the state's filing deadline, Sen. Steve Daines withdrew his name from the ballot, ending his bid for a third term. He had previously been widely expected t
wikipedia	OK	0.2s	3	Fetched 3 Wikipedia entries (0 missing pages).
code_execution	OK	53.0s	0	## Base-Rate & Structural Model Results — GOP Hold Probability, MT Senate 2026 Historical base rate (landslide-state same-party incumbents/seats, midterms since 1990): - Across 17 identified analogous cases (2010 Dem incumbents in Obama+15-45 states, 2018 GOP incumbents/retirements in Trump+15-

3. Evidence Brief Sonnet 5 · 7660 chars

# Current state Montana's 2026 Senate race is a three-way contest following Sen. Steve Daines' surprise last-minute retirement; Republican nominee Kurt Alme (US Attorney, Daines-endorsed) leads a divided field against Democrat Alani Bankhead and Trump-critical independent Seth Bodnar (backed by ex-Sen. Jon Tester and some Democratic leaders). The race remains unresolved (election is 2026-11-03); resolution requires AP+Fox+NBC consensus call or certification. # Timeline of key events - 2026-03-04: Daines withdraws minutes before filing deadline, ending re-election bid; endorses Kurt Alme, who files same day; Trump endorses Alme shortly after (confirmed — Wikipedia, Fox News, Legis1). - 2026-06-02: Primaries held. Alme wins GOP nomination unopposed-effectively with 76.2%; Bankhead wins Dem primary with 43.7% over Neill and Black Wolf (confirmed — Wikipedia). - 2026-06 (post-primary): Bodnar (independent, Tester-backed) launches campaign after resigning as University of Montana president (confirmed). - 2026-07-16: Fundraising reports show Bodnar leads total contributions (~$1.12M) but Bankhead lags badly (~$35K quarter); Alme has ~$801K incl. $350K transfer from Daines' campaign (confirmed — Daily Montanan). - 2026-07-27 to 09-13: National outlets (NPR, CBS, CNN) rate MT as non-competitive/"solidly R," focusing attention on ME, NC, OH, IA, TX, MN instead (reported). - 2026-09-05 to 09-08: Reports confirm Democratic Party leaders quietly back Bodnar over own nominee Bankhead; three-way vote-split favors Alme (reported — CNN, Semafor). - 2026-09-11: MTFP-Rutgers poll: Alme leads Bodnar by 8 points, Bankhead far behind (reported). - 2026-09-14/15: Quantus Insights poll: Alme 43.6%, Bodnar 24.3%, Bankhead 23.1% — 19.3-pt Alme lead (reported, partisan-adjacent pollster). - 2026-09 (Peak Insights, Alme-commissioned): Alme 44%, Bodnar 22%, Bankhead 19% (reported, internal poll — lower confidence). - Decision Desk HQ aggregate (~Sept): Alme 44%, Bodnar 26%, Bankhead 21%; DDHQ model gives Alme ~90% win probability (reported). # Event Will the Republicans win the Montana Senate race in 2026? # Outcomes to forecast Yes (Republican wins) / No (Republican does not win) # Kalshi market anchor No direct Kalshi price returned for this ticker in raw research (kalshi_related found no exact "Montana Senate" market, only broader Senate-control markets). Polymarket's parallel/identical-question market prices **Republican win at 92.5% YES** (7d +1.5%, 30d flat, range 76.5%-93%, $65K volume, 91 days of data) — this is the best available cross-platform anchor and should be treated as the consensus baseline for Kalshi as well. # Resolution source No resolution_source tool result provided; resolution will be AP/Fox/NBC race call or official MT certification post-2026-11-03 election. Not yet resolved. # Sub-question answers 1. **Daines re-election/challenger?** Daines is NOT running — he withdrew minutes before the 2026-03-04 filing deadline and endorsed Kurt Alme, who filed immediately and won the GOP primary with 76.2% as the only major candidate (Wikipedia, Fox News). 2. **Democratic nominee/strength?** Alani Bankhead (Air Force officer) won the Dem primary with 43.7% but has weak fundraising (~$35K/quarter, ~$21K cash on hand) and trails badly in polls (19-23%); Democratic leadership has quietly shifted support to independent Bodnar instead (CNN, Daily Montanan). 3. **Polls/ratings?** September 2026 polls show Alme leading 43-44%, Bodnar 22-26%, Bankhead 19-23% — Alme leads by 8-19 points depending on poll. Cook, Sabato's Crystal Ball, and Inside Elections all rate the seat Solid/Likely Republican (KTVH, Legis1, 270toWin). 4. **National environment?** GOP holds 53-47 Senate majority; national environment estimated D+3 to D+8 in code_execution model; MT (Trump+20 in 2024) is well outside the competitive tier, ranked below ME, NC, OH, IA, TX (CBS, NPR). 5. **Third-party/independent factor?** Yes — independent Seth Bodnar (Tester-backed) is a serious factor, drawing 22-26% and splitting anti-Republican vote with Bankhead; this split is the primary reason Alme leads comfortably despite an open seat (CNN, Semafor, DDHQ). Bodnar does NOT count as "Republican" for resolution but his presence helps the Republican outcome by dividing opposition. 6. **Historical base rate?** code_execution analysis: 17/17 (100%) same-party incumbents/open seats held in 15+pt landslide states across 2010/2018/2022 midterms (small-N, survivorship-biased); open-seat/retirement cases (TN, UT 2018) also held. 7. **Kalshi vs Polymarket?** No Kalshi-specific price found for this exact ticker in research; Polymarket YES=92.5%. Broader Kalshi/Polymarket Senate-control markets show Dem control priced 38.5-60.5% depending on market/platform — MT specifically is not treated as a swing factor in those aggregates. # Key facts (high-confidence, factual) 1. [Wikipedia] Daines withdrew 2026-03-04, endorsed Alme same day; first open MT Senate seat since 1976. 2. [Wikipedia] Alme won GOP primary 76.2%; Bankhead won Dem primary 43.7% (2026-06-02). 3. [Daily Montanan] Bodnar led fundraising (~$1.12M) but Alme had more cash-on-hand/institutional support by September. 4. [Multiple polls, Sept 2026] Alme leads 3-way race by 8-19 points; Bankhead consistently third. 5. [KTVH/270toWin] Cook/Sabato/Inside Elections rate MT Solid/Likely R, non-competitive nationally. # Cross-market signals - Kalshi related: No exact MT market found; broader Senate-control markets (Dem sweep 50%, Dem Senate 56 seats 86%) don't isolate MT. - Polymarket: This exact market prices Republican win 92.5% (up from 76.5% low, stable 30d). - Polymarket related: "Republican Party control Senate" 38.5% YES (national, not MT-specific); illustrates MT is priced far more R-favorable than Senate control overall, consistent with split-opposition dynamic. - Sportsbook: none found. # Analyst opinions and speculation - DDHQ model/newsletter: ~90% Alme win probability, attributes Alme's lead directly to Democratic Party's failure to consolidate behind Bodnar (Semafor, DDHQ Substack). - CNN/Washington Post analysts frame Bodnar as a national model for Dem-adjacent independents in red states, but note Bankhead's refusal to withdraw undermines that strategy in MT specifically. - Caveat (reported, lower confidence): head-to-head (2-way) polls after the primary showed Bodnar competitive with or leading Alme — suggesting Republican win probability is somewhat contingent on continued 3-way vote splitting through November. # Directional lean per outcome - **Yes (Republican win)**: Strong — Trump+20 state, official R/L ratings, consistent multi-poll leads (8-19 pts), opposition vote-split, Polymarket 92.5%, base-rate model ~86-90%. - **No**: Weak but non-trivial — open-seat penalty (no incumbent), Bankhead refusing to drop out could still shift late if Dem-Bodnar consolidation occurs, head-to-head polls show closer Bodnar-Alme margin; national environment (D+3-D+8) is a modest headwind. # Gaps / unknowns - No confirmed direct Kalshi price for this specific ticker was returned (only Polymarket). - Whether Bankhead formally withdraws/endorses Bodnar before November is unresolved and could tighten the race materially. - General election (not just primary) polling trend Oct-Nov not covered. # Calibration anchors - Polymarket YES (cross-market proxy for Kalshi): 92.5%, stable/rising. - Base-rate model (code_execution): 82-90% central range for structural/historical GOP win probability in this scenario. - Historical precedent: 100% (17/17) same-party retention rate in 15+pt landslide-lean states in past three midterms (small-N caveat).

4. Forecasters 5 draws · Fable 5.1 + GPT-5.6 Sol

claude-fable-5-1

68% conf

Yes	91%
No	9%

Republican Kurt Alme leads a three-way race by 8-19 points across multiple September polls (MTFP-Rutgers, Quantus, DDHQ aggregate 44-26-21), in a Trump+20 state rated Solid/Likely R by Cook, Sabato, and Inside Elections. The anti-Republican vote is split between Democrat Bankhead and Tester-backed independent Bodnar, with Democratic leadership unable to force consolidation; DDHQ's model gives Alme ~90% and Polymarket prices the Republican at 92.5% (the best available cross-platform anchor absent a direct Kalshi quote). The main downside risks are an open-seat penalty in a D-leaning national environment and the possibility that Bankhead withdraws or voters consolidate behind Bodnar, since head-to-head polling showed a closer Alme-Bodnar margin. I shade slightly below the market to account for open-seat and consolidation tail risk with ~7 weeks remaining.

claude-fable-5-1

70% conf

Yes	90%
No	10%

Republican Kurt Alme leads a three-way race by 8-19 points in all September polls (Alme ~44%, Bodnar ~22-26%, Bankhead ~19-23%), with Cook/Sabato/Inside Elections rating the seat Solid/Likely R in a Trump+20 state. The Polymarket parallel market prices a Republican win at 92.5% (stable, rising), and DDHQ's model gives Alme ~90%, consistent with the 82-90% base-rate range. The main residual risk is late consolidation of anti-GOP voters behind independent Bodnar (head-to-head polls reportedly closer) plus an open-seat penalty and a D+3-8 national environment, so I shade slightly below the market anchor.

claude-fable-5-1

62% conf

Yes	90%
No	10%

Republican Kurt Alme leads a three-way race by 8-19 points in all September polls (DDHQ aggregate 44-26-21), is Trump- and Daines-endorsed in a Trump+20 state, and Cook/Sabato/Inside Elections rate the seat Solid/Likely R; the Democratic vote is split between nominee Bankhead and Tester-backed independent Bodnar, which DDHQ credits for Alme's ~90% model win probability. Polymarket prices a Republican win at 92.5% (stable/rising), and the historical retention base rate in 15+pt landslide states is near 100%. I shade slightly below the market because the seat is open (no incumbent), the national environment is estimated D+3 to D+8, and head-to-head polling reportedly shows Bodnar competitive—so a late Bankhead withdrawal or Democratic consolidation is a real, if unlikely, tail risk with several weeks until Election Day.

gpt-5.6-sol

79% conf

Yes	92%
No	8%

The 92.5% Polymarket YES price is the best available consensus anchor, and the evidence broadly supports staying near it. Alme leads every cited September poll by 8–19 points in a state Trump won by 20, while major forecasters rate the race Solid or Likely Republican. Bankhead’s weak fundraising and continued presence split the anti-Republican vote with Bodnar, although a late consolidation behind Bodnar would create meaningful downside because two-way polling has reportedly been closer. The favorable state baseline and historical retention record outweigh the open-seat and Democratic-national-environment risks, supporting a modest adjustment to 92%.

gpt-5.6-sol

78% conf

Yes	92%
No	8%

The 92.5% Polymarket price is the best available consensus anchor because no direct Kalshi market was found. Alme leads every cited September poll by 8-19 points in a state Trump won by 20, while major forecasters rate the race Solid or Likely Republican. Bankhead's weak campaign and continued presence split the anti-Republican vote with Bodnar, materially strengthening Alme despite the open seat. I shade slightly below the anchor because Democratic consolidation behind Bodnar remains possible and head-to-head polling suggests that scenario would be substantially more competitive.

6. Final plain mean of 5 draws

91% (71% confidence)

Yes: 91% No: 9%

Mean of 5 draws (0.91, 0.90, 0.90, 0.92, 0.92). Republican Kurt Alme leads a three-way race by 8-19 points across multiple September polls (MTFP-Rutgers, Quantus, DDHQ aggregate 44-26-21), in a Trump+20 state rated Solid/Likely R by Cook, Sabato, and Inside Elections. The anti-Republican vote is split between Democrat Bankhead and Tester-backed independent Bodnar, with Democratic leadership unable to force consolidation; DDHQ's model gives Alme ~90% and Polymarket prices the Republican at 92.5% (the best available cross-platform anchor absent a direct Kalshi quote). The main downside risks are an open-seat penalty in a D-leaning national environment and the possibility that Bankhead withdraws or voters consolidate behind Bodnar, since head-to-head polling showed a closer Alme-Bodnar margin. I shade slightly below the market to account for open-seat and consolidation tail risk with ~7 weeks remaining.

Pipeline Timing

Total pipeline time: 119.8s

Per-tool research timings shown in the Research section above.