Staggered Senate
Senators serve four-year terms; half the seats are on the ballot each election.
Montana › Montana State Senate · November 3, 2026 · Updated Oct 16, 2026
Montana State Senate District 4
Regier is very likely to win: Regier wins in more than 99 of every 100 simulations.
Waterman (D)
<1%
chance of winning
Regier (R)
>99%
- Average margin
- R+23.5
- 80% of outcomes
- R+33 to R+14
- Partisan lean
- R+32
- Polls
- No pollsmodel only
Regier is very likely to win: Regier wins in more than 99 of every 100 simulations.
Waterman (D)
1%
chance of winning
Regier (R)
99%
- Average margin
- R+28.3
- 80% of outcomes
- R+41 to R+16
- Partisan lean
- R+32
- Polls
- No pollsmodel only
How this race is decided
Range of outcomes
Final margin across our simulations; the white dashes mark the middle 80%.
The candidates
Democratic
Kyle Waterman
Nominee for this district in 2022 and for the second senate district in 2020
- Experience
- No elected office
Republican
Amy Regier
State representative from the 6th district (2021–present)
- Experience
- State legislature
What goes into the forecast
Every ingredient's estimate of the final margin.
- National environment
- D+9.5Election Day forecast
- Montana state offices
- +0.0Polls for governor, statewide and legislative races · details
- Environment here
- D+9.5Used by the fundamentals
- Swing reaching this office
- 58%Of a shift in the environment, from past legislative races since 2016
- Mountain West adjustment
- +1.2How legislative races in the region have run against lean and environment lately
Each estimate is a margin before national and statewide uncertainty is simulated. Horizon blends polls, fundamentals and a little of the similar-places estimate, weighting each by how precise it is; Pulse uses polls and similar places only.
Fundamentals inputs
| Incumbency (+1 D, −1 R) | 0 |
| Fundraising edge (log ratio of individual money) | -0.52 |
| Elected-experience edge | -0.67 |
| First-term incumbent | 0 |
| Seat's last result vs. expectation | 0 |
| Incumbent's last result vs. expectation | 0 |
Polls
No public polls of this race. The forecast relies on fundamentals and on polling of similar places in the state.
The district
Lean R+32: how much more Democratic or Republican than the nation it votes for president.
Presidential vote
Precinct results re-aggregated to the current district lines.
Who lives here
- Population
- 22,418
- People per km²
- 587
- Adults with a B.A.+
- 31%
- White, no degree
- 62%of adults
- White 90%
- Hispanic 3%
- Asian 1%
- Other / multiracial 6%
American Community Survey 2020–2024, aggregated from census tracts.
Past results
Results in the same-numbered district; earlier elections may have used different lines.
2024 President Vote in this district
10,403 two-party votes · R+33.2 · R+31.7 vs. the nation✓ Donald Trump (R)66.6%
Kamala Harris (D)33.4%
2022 Earlier district lines
8,329 votes · R+24.4✓ John Fuller (R)62.2%
Kyle Waterman (D)37.8%
2020 President Vote in this district
11,263 two-party votes · R+27.8 · R+32.4 vs. the nation✓ Donald Trump (R)63.9%
Joe Biden (D)36.1%
2018 Earlier district lines
8,723 votes · R+29.0✓ Mark W Blasdel (R)64.5%
Diane Taylor-Mahnke (D)35.5%
2016 President Vote in this district
7,173 two-party votes · R+36.7 · R+39.0 vs. the nation✓ Donald Trump (R)68.4%
Hillary Clinton (D)31.6%
2014 Earlier district lines
5,796 votes · R+36.6✓ Mark W Blasdel (R)68.3%
Diane Taylor (D)31.7%