Cross-party nominations
A candidate can be nominated by several parties, such as Working Families or the Independent Party, and the ballot lists all of them next to one name. The forecast counts the candidate's votes once, under their main party.
Oregon · 2026 forecast · Updated Oct 16, 2026
Who will control the Oregon State Senate?
15 of 30 seats are on the ballot; the others are elected in alternate years. 16 seats make a majority. 20 make the two-thirds supermajority that can override a veto.
Democrats are very likely to control the Oregon State Senate (>99%).
Democrats
>99%
chance of control
Republicans
<1%
- Avg. D seats
- 19.380% range 18–21
- Avg. R seats
- 10.780% range 9–12
- Now
- 18 D · 12 R15 up this year
Chance Democrats win a two-thirds supermajority (20+ seats): 41%
18 D nowMarks: two-thirds supermajority for each party12 R now
Democrats are very likely to control the Oregon State Senate (>99%).
Democrats
>99%
chance of control
Republicans
<1%
- Avg. D seats
- 19.380% range 18–21
- Avg. R seats
- 10.780% range 9–12
- Now
- 18 D · 12 R15 up this year
Chance Democrats win a two-thirds supermajority (20+ seats): 43%
18 D nowMarks: two-thirds supermajority for each party12 R now
- Solid D
- Likely D
- Lean D
- Toss-up
- Lean R
- Likely R
- Solid R
- Holdover, not up this year
Race ratings
All 15 races, grouped by the leader's chance of winning.
1 seat projected to flip: 1 R→D.
1 seat projected to flip: 1 R→D.
Columns follow the chance of winning: Toss-up 40–60%, Lean 60–80%, Likely 80–95%, Solid 95%+. The square shows who holds the seat now (■ Democrats, ■ Republicans). flip: projected to change parties, in the color of the party favored to gain it. Faded: no major-party opponent.
The map
Each district colored by the leader's chance of winning. Hover for details; click for the race.
Oregon
Portland
- Solid D
- Likely D
- Lean D
- Toss-up
- Lean R
- Likely R
- Solid R
- Projected flip (stripes: party holding it now)
Seats to watch
The closest races (Lean or Toss-up, Horizon), and the seats most likely to change parties.
Closest races
Most likely to flip
SD-11Virginia StapletonTracy CramerD flipD flip83%to flip83%to flip SD-16Rachel ArmitageCourtney Bangs37%to flip39%to flip SD-26Nicole BassettJeff Helfrich22%to flip30%to flip SD-3Denise KrauseBrad Hicks7%to flip11%to flip SD-20Mark MeekMichelle Stroh3%to flip7%to flip SD-10Deb PattersonAngela Plowhead1%to flip5%to flip SD-6Sierrah WilliamsJack Tibbetts1%to flip2%to flip SD-8Sara Gelser BlouinValerie Draper Woldeit<1%to flip2%to flip SD-15Myrna MuñozHarold Hutchison<1%to flip1%to flip SD-13Courtney Neron MisslinGlenn Lancaster<1%to flip1%to flip
How this chamber is elected
Rules that shape these races and the forecast.
Staggered Senate
Senators serve four-year terms; half the seats are on the ballot each election.
15 of 30 seats on the ballot; 15 holdovers (7 D, 8 R) serve until a later election.
Two-thirds quorum
Each chamber needs two-thirds of its members present to do business, so a minority holding more than a third of seats can block votes by walking out. Members with ten unexcused absences in a session cannot run for re-election (Measure 113).
How the odds have moved
Chance of winning control, by forecast date.
Updated nightly. Each day is the current model run on the polls that had ended by then (how).
Updated nightly. Each day is the current model run on the polls that had ended by then (how).
Every outcome we simulated
Democratic seats across 40,000 simulations. Darker bars: the middle 80%.
Every race
15 races, 2 without a contest between the major parties.
15 races
| District | Candidates | Chance of winning (D · R) | Avg. margin | Rating | Lean | Polls |
|---|---|---|---|---|---|---|
| SD-3 | ● Denise Krause● Brad HicksAlso: Clay Bearnson (I) | D+11.0D+12.1 | D+13 | — | ||
| SD-4 | ● Floyd ProzanskiINC● No Republican | Democrat unopposedDemocrat unopposed | — | D+41 | — | |
| SD-6 | ● Sierrah Williams● Jack TibbettsAlso: Caleb Ticer (L) | R+19.6R+20.8 | R+23 | — | ||
| SD-7 | ● James Manning Jr.INC● Jack Huff | D+29.7D+28.3 | D+31 | — | ||
| SD-8 | ● Sara Gelser BlouinINC● Valerie Draper Woldeit | D+24.6D+22.6 | D+25 | — | ||
| SD-10 | ● Deb PattersonINC● Angela Plowhead | D+18.0D+16.3 | D+16 | — | ||
| SD-11D flipD flip | ● Virginia Stapleton● Tracy Cramer | D+7.1D+9.4 | D+6 | — | ||
| SD-13 | ● Courtney Neron MisslinINC● Glenn LancasterAlso: Tim E Nelson (L) | D+30.0D+29.0 | D+30 | — | ||
| SD-15 | ● Myrna Muñoz● Harold Hutchison | D+26.3D+27.2 | D+27 | — | ||
| SD-16 | ● Rachel Armitage● Courtney BangsAlso: Melisa Finkle (I) | R+2.4R+2.6 | R+3 | — | ||
| SD-17 | ● Lisa ReynoldsINC● John Chee | D+61.2D+66.6 | D+64 | — | ||
| SD-19 | ● Rob WagnerINC● Mary Dirksen | D+42.7D+47.3 | D+46 | — | ||
| SD-20 | ● Mark MeekINC● Michelle Stroh | D+15.0D+14.4 | D+15 | — | ||
| SD-24 | ● Kayse JamaINC● No Republican | Democrat unopposedDemocrat unopposed | — | D+24 | — | |
| SD-26 | ● Nicole Bassett● Jeff Helfrich | R+5.4R+4.8 | R+6 | — |
Lean: how much more Democratic (D+) or Republican (R+) the place voted for president than the nation (2024 weighted 75%, 2020 25%). Ratings follow the chance of winning: Toss-up 40–60%, Lean 60–80%, Likely 80–95%, Solid 95%+. INC = incumbent running. D flip / R flip: another party is favored (60% or more) over the party holding the seat now (hover for the chance it changes parties); Flip risk: the seat is a toss-up (40–60%). Badges mark election rules (hover or long-press for details): RCV = ranked-choice voting; Top two / Top four = the leading primary finishers advance; All-party = every candidate on one November ballot; TBD = no candidate list yet, forecast for the seat's party against a generic challenger.