Read the result, then trace back to the races and sources.
Each race sets the two modelled candidates against each other: Democrat and Republican, or independent and Republican in Idaho, Montana, Nebraska and South Dakota. Another candidate's chance is bounded by the polls: below 0.5% in Alaska, Maine and Nebraska; at most 1.7% in Montana. A detailed calculation sheet is available for each of the 35 races. The figures are recomputed every day.
Polls through 2026-10-03 · election at T−31 · calibration at T−47
EXPLORE THE UNITED STATES
The Senate races, in three views
EXPLORE THE RACES3 vues · same selection
National view 50 States · 35 races
Tab moves through the states. Enter opens the sheet. The three views keep the selection. +/− zooms; “Frame” centers the race. “Pan” enables moving with the mouse or finger. Escape closes full screen.
R more frequent in the draws≈ 50/50D more frequentI more frequentNo race in play
NATIONAL SIMULATION
Balance of power and seat distribution
Democrats47.95mean seats · intervalle 90%: 45–51
Republicans49.10mean seats · intervalle 90%: 46–53
Independents2.96mean seats · intervalle 90%: 2–4
Control, without assigning the new independents
Democratic caucus
38.9%
Republican caucus
42.7%
Depends on the independents
18.4%
The third state corresponds to draws where control depends on the organizing choice of one or more new independents. If these newly elected members caucus with the Democrats, the chances of Democratic control are 57.3%.
Caucus scenarios, only if the independents are elected
These scenarios receive no probability of their own.
Democratic caucus
38.9%
Republican caucus
42.7%
Depends on the independents
18.4%
Seat distribution of the Democratic caucus
Mean: 49.95 seats · intervalle central 90%: 47–53.
MECHANICAL PROBABILITY ZONE
Races in the interval 25–75%
This box shows all races where each of the two modeled candidates keeps at least 25% probability. The order is alphabetical by state.
| Race | Modeled candidates | P(opposition) | P(R) | Center | Axis |
|---|---|---|---|---|---|
| Alaska | Mary Peltola (D)Dan S. Sullivan (R) | 32.9% | 67.1% | -3.2 pts | D/R |
| South Dakota | Brian Bengs (I)Mike Rounds (R) | 34.0% | 66.0% | -5.0 pts | I/R |
| Iowa | Josh Turek (D)Ashley Hinson (R) | 33.6% | 66.4% | -3.1 pts | D/R |
| Maine | Troy D. Jackson (D)Susan M. Collins (R) | 63.0% | 37.0% | 2.4 pts | D/R |
| Michigan | Abdul El-Sayed (D)Mike Rogers (R) | 63.5% | 36.5% | 2.5 pts | D/R |
| Minnesota | Peggy Flanagan (D)Michele Tafoya (R) | 69.4% | 30.6% | 3.7 pts | D/R |
| Nebraska | Dan Osborn (I)Pete Ricketts (R) | 41.6% | 58.4% | -2.6 pts | I/R |
| Ohio | Sherrod Brown (D)Jon Husted (R) | 56.5% | 43.5% | 1.2 pts | D/R |
| Texas | James Talarico (D)Ken Paxton (R) | 48.4% | 51.6% | -0.3 pts | D/R |
The threshold changes no probability and creates no additional scientific category.
COMPARE THE SEAT'S LAST ELECTION AND THE FORECAST 2026
Historical reference ↔ Forecast center
The Senate is renewed by class: the reference is therefore not a single national election. For each D/R race, the left layer shows the seat's last archived Senate result (2020 for the cycle's regular races, 2022 for the two specials in the snapshot) and the right layer the center 2026. The I/R races keep a different axis and are deliberately neutralized.
SEAT'S LAST ELECTIONyear varies by race
FORECAST 2026forecast center
All 2026All history
R +40D/R tieD +40Beige: I/R axis or non-comparable history
Select a race.The comparison does not alter the model.
Historical source: the seat's last archived Senate result, with its year. Differences are computed only when both axes are D−R.
LOCAL SIGNAL
Poll aggregates and coverage
AK-SEN · Mary Peltola / Dan S. Sullivan
Conditional signal1.42 pts
Latest fieldwork2026-10-01
Clusters10
Primary clusters indicatedNot measured
IA-SEN · Josh Turek / Ashley Hinson
Conditional signal0.56 pts
Latest fieldwork2026-10-01
Clusters17
Primary clusters indicatedNot measured
KS-SEN · Adam Hamilton / Roger Marshall
Conditional signal0.06 pts
Latest fieldwork2026-10-01
Clusters7
Primary clusters indicatedNot measured
ME-SEN · Troy D. Jackson / Susan M. Collins
Conditional signal0.47 pts
Latest fieldwork2026-10-01
Clusters17
Primary clusters indicatedNot measured
OH-SEN-SPECIAL · Sherrod Brown / Jon Husted
Conditional signal3.97 pts
Latest fieldwork2026-10-01
Clusters14
Primary clusters indicatedNot measured
ID-SEN · Todd Achilles / Jim Risch
Conditional signal-14.68 pts
Latest fieldwork2026-09-30
Clusters5
Primary clusters indicatedNot measured
MI-SEN · Abdul El-Sayed / Mike Rogers
Conditional signal3.15 pts
Latest fieldwork2026-09-30
Clusters29
Primary clusters indicatedNot measured
NE-SEN · Dan Osborn / Pete Ricketts
Conditional signal-2.56 pts
Latest fieldwork2026-09-30
Clusters6
Primary clusters indicatedNot measured
TX-SEN · James Talarico / Ken Paxton
Conditional signal2.64 pts
Latest fieldwork2026-09-30
Clusters27
Primary clusters indicatedNot measured
MN-SEN · Peggy Flanagan / Michele Tafoya
Conditional signal1.99 pts
Latest fieldwork2026-09-29
Clusters7
Primary clusters indicatedNot measured
NC-SEN · Roy Cooper / Michael Whatley
Conditional signal9.11 pts
Latest fieldwork2026-09-29
Clusters19
Primary clusters indicatedNot measured
SC-SEN · Annie Andrews / Darline Graham
Conditional signal-1.96 pts
Latest fieldwork2026-09-29
Clusters7
Primary clusters indicatedNot measured
FL-SEN-SPECIAL · Angie Nixon / Ashley Moody
Conditional signal-4.29 pts
Latest fieldwork2026-09-27
Clusters7
Primary clusters indicatedNot measured
NH-SEN · Chris Pappas / John E. Sununu
Conditional signal6.64 pts
Latest fieldwork2026-09-27
Clusters9
Primary clusters indicatedNot measured
SD-SEN · Brian Bengs / Mike Rounds
Conditional signal-4.99 pts
Latest fieldwork2026-09-27
Clusters3
Primary clusters indicatedNot measured
AL-SEN · Everett Wess / Barry Moore
Conditional signal-18.99 pts
Latest fieldwork2026-09-25
Clusters1
Primary clusters indicatedNot measured
MT-SEN · Seth Bodnar / Kurt Alme
Conditional signal-16.05 pts
Latest fieldwork2026-09-24
Clusters9
Primary clusters indicatedNot measured
GA-SEN · Jon Ossoff / Mike Collins
Conditional signal9.18 pts
Latest fieldwork2026-09-23
Clusters8
Primary clusters indicatedNot measured
MA-SEN · Edward J. Markey / John Deaton
Conditional signal29.80 pts
Latest fieldwork2026-09-22
Clusters4
Primary clusters indicatedNot measured
RI-SEN · John F. Reed / Raymond T. McKay
Conditional signal24.18 pts
Latest fieldwork2026-09-21
Clusters2
Primary clusters indicatedNot measured
LA-SEN · "Jamie" Davis / Julia Letlow
Conditional signal-5.13 pts
Latest fieldwork2026-09-19
Clusters2
Primary clusters indicatedNot measured
NM-SEN · Ben R. Luján / Larry E. Marker (R primary write-in)
Conditional signal16.48 pts
Latest fieldwork2026-08-28
Clusters1
Primary clusters indicatedNot measured
KY-SEN · Charles Booker / Andy Barr
Conditional signal-10.11 pts
Latest fieldwork2026-08-27
Clusters1
Primary clusters indicatedNot measured
TN-SEN · Marquita Bradshaw / Bill Hagerty
Conditional signal-26.10 pts
Latest fieldwork2026-08-26
Clusters1
Primary clusters indicatedNot measured
AR-SEN · Hallie Shoffner / Tom Cotton
Conditional signal-5.99 pts
Latest fieldwork2026-08-18
Clusters3
Primary clusters indicatedNot measured
MS-SEN · Scott Colom / Cindy Hyde-Smith
Conditional signal-7.31 pts
Latest fieldwork2026-08-15
Clusters1
Primary clusters indicatedNot measured
OK-SEN · N'Kiyla Jasmine Thomas / Kevin Hern
Conditional signal-32.43 pts
Latest fieldwork2026-08-06
Clusters1
Primary clusters indicatedNot measured
CO-SEN · John Hickenlooper / Mark Baisley
Conditional signal13.04 pts
Latest fieldwork2026-07-13
Clusters1
Primary clusters indicatedNot measured
VA-SEN · Mark R. Warner / Bert Mizusawa
Conditional signal22.18 pts
Latest fieldwork2026-06-16
Clusters2
Primary clusters indicatedNot measured
DE-SEN · Chris Coons / Michael "Dr. Mike" Katz
Conditional signal— pts
Latest fieldwork—
Clusters0
Primary clusters indicatedNot measured
IL-SEN · Juliana Stratton / Don Tracy
Conditional signal— pts
Latest fieldwork—
Clusters0
Primary clusters indicatedNot measured
NJ-SEN · Cory Booker / Justin Murphy
Conditional signal— pts
Latest fieldwork—
Clusters0
Primary clusters indicatedNot measured
OR-SEN · Jeff Merkley / David Brock Smith
Conditional signal— pts
Latest fieldwork—
Clusters0
Primary clusters indicatedNot measured
WV-SEN · Rachel Fetty Anderson / Shelley Moore Capito
Conditional signal— pts
Latest fieldwork—
Clusters0
Primary clusters indicatedNot measured
WY-SEN · James Byrd / Harriet Hageman
Conditional signal— pts
Latest fieldwork—
Clusters0
Primary clusters indicatedNot measured
THE 35 COURSES · AT A GLANCE
Readable results before the technical layers
As for the House, the main table favors the electoral reading: central score of the modeled pair, lead, probabilities, interval and freshness of the signal. Calculation details remain accessible without cluttering the first reading.
| Race | D/I candidate | R candidate | D/I score | R score | Lead | P(D/I) | P(R) | Interval 90% | Signal | |
|---|---|---|---|---|---|---|---|---|---|---|
| Alaska · Regular | D · Mary Peltola | R · Dan S. Sullivan | 48.4% | 51.6% | R +3.2 | 32.9% | 67.1% | -15.2 to 8.7 | 10 clusters2026-10-01 · J−2 | |
| Alabama · Regular | D · Everett Wess | R · Barry Moore | 39.5% | 60.5% | R +20.9 | 0.2% | 99.8% | -32.9 to -9.0 | 1 cluster2026-09-25 · J−8 | |
| Arkansas · Regular | D · Hallie Shoffner | R · Tom Cotton | 42.8% | 57.2% | R +14.4 | 2.4% | 97.6% | -26.4 to -2.4 | 3 clusters2026-08-18 · J−46 | |
| Colorado · Regular | D · John Hickenlooper | R · Mark Baisley | 58.5% | 41.5% | D +17.0 | 99.0% | 1.0% | 5.1 to 29.0 | 1 cluster2026-07-13 · J−82 | |
| Delaware · Regular | D · Chris Coons | R · Michael "Dr. Mike" Katz | 63.0% | 37.0% | D +26.0 | 99.9% | 0.1% | 11.8 to 40.2 | Structure onlyno poll retained | |
| Florida · Special | D · Angie Nixon | R · Ashley Moody | 46.5% | 53.5% | R +7.1 | 16.5% | 83.5% | -19.1 to 4.9 | 7 clusters2026-09-27 · J−6 | |
| Georgia · Regular | D · Jon Ossoff | R · Mike Collins | 54.9% | 45.1% | D +9.7 | 90.9% | 9.1% | -2.3 to 21.7 | 8 clusters2026-09-23 · J−10 | |
| Iowa · Regular | D · Josh Turek | R · Ashley Hinson | 48.5% | 51.5% | R +3.1 | 33.6% | 66.4% | -15.1 to 8.9 | 17 clusters2026-10-01 · J−2 | |
| Idaho · Regular | I · Todd Achilles | R · Jim Risch | 42.7% | 57.3% | R +14.7 | 11.2% | 88.8% | -34.5 to 5.2 | 5 clusters2026-09-30 · J−3 | |
| Illinois · Regular | D · Juliana Stratton | R · Don Tracy | 56.2% | 43.8% | D +12.4 | 92.4% | 7.6% | -1.8 to 26.6 | Structure onlyno poll retained | |
| Kansas · Regular | D · Adam Hamilton | R · Roger Marshall | 47.4% | 52.6% | R +5.2 | 23.7% | 76.3% | -17.2 to 6.8 | 7 clusters2026-10-01 · J−2 | |
| Kentucky · Regular | D · Charles Booker | R · Andy Barr | 42.1% | 57.9% | R +15.8 | 1.5% | 98.5% | -27.7 to -3.8 | 1 cluster2026-08-27 · J−37 | |
| Louisiana · Regular | D · "Jamie" Davis | R · Julia Letlow | 44.9% | 55.1% | R +10.2 | 8.1% | 91.9% | -22.1 to 1.8 | 2 clusters2026-09-19 · J−14 | |
| Massachusetts · Regular | D · Edward J. Markey | R · John Deaton | 66.5% | 33.5% | D +33.1 | 100.0% | 0.0% | 21.1 to 45.1 | 4 clusters2026-09-22 · J−11 | |
| Maine · Regular | D · Troy D. Jackson | R · Susan M. Collins | 51.2% | 48.8% | D +2.4 | 63.0% | 37.0% | -9.6 to 14.4 | 17 clusters2026-10-01 · J−2 | |
| Michigan · Regular | D · Abdul El-Sayed | R · Mike Rogers | 51.3% | 48.7% | D +2.5 | 63.5% | 36.5% | -9.5 to 14.5 | 29 clusters2026-09-30 · J−3 | |
| Minnesota · Regular | D · Peggy Flanagan | R · Michele Tafoya | 51.8% | 48.2% | D +3.7 | 69.4% | 30.6% | -8.3 to 15.7 | 7 clusters2026-09-29 · J−4 | |
| Mississippi · Regular | D · Scott Colom | R · Cindy Hyde-Smith | 44.3% | 55.7% | R +11.4 | 5.9% | 94.1% | -23.4 to 0.6 | 1 cluster2026-08-15 · J−49 | |
| Montana · Regular | I · Seth Bodnar | R · Kurt Alme | 42.0% | 58.0% | R +16.0 | 9.2% | 90.8% | -35.9 to 3.8 | 9 clusters2026-09-24 · J−9 | |
| North Carolina · Regular | D · Roy Cooper | R · Michael Whatley | 56.5% | 43.5% | D +12.9 | 96.2% | 3.8% | 1.0 to 24.9 | 19 clusters2026-09-29 · J−4 | |
| Nebraska · Regular | I · Dan Osborn | R · Pete Ricketts | 48.7% | 51.3% | R +2.6 | 41.6% | 58.4% | -22.4 to 17.3 | 6 clusters2026-09-30 · J−3 | |
| New Hampshire · Regular | D · Chris Pappas | R · John E. Sununu | 52.5% | 47.5% | D +5.1 | 75.6% | 24.4% | -6.9 to 17.0 | 9 clusters2026-09-27 · J−6 | |
| New Jersey · Regular | D · Cory Booker | R · Justin Murphy | 59.9% | 40.1% | D +19.8 | 98.9% | 1.1% | 5.6 to 33.9 | Structure onlyno poll retained | |
| New Mexico · Regular | D · Ben R. Luján | R · Larry E. Marker (R primary write-in) | 58.5% | 41.5% | D +17.0 | 99.0% | 1.0% | 5.1 to 29.0 | 1 cluster2026-08-28 · J−36 | |
| Ohio · Special | D · Sherrod Brown | R · Jon Husted | 50.6% | 49.4% | D +1.2 | 56.5% | 43.5% | -10.8 to 13.2 | 14 clusters2026-10-01 · J−2 | |
| Oklahoma · Regular | D · N'Kiyla Jasmine Thomas | R · Kevin Hern | 35.9% | 64.1% | R +28.1 | 0.0% | 100.0% | -40.1 to -16.2 | 1 cluster2026-08-06 · J−58 | |
| Oregon · Regular | D · Jeff Merkley | R · David Brock Smith | 62.8% | 37.2% | D +25.6 | 99.9% | 0.1% | 11.5 to 39.8 | Structure onlyno poll retained | |
| Rhode Island · Regular | D · John F. Reed | R · Raymond T. McKay | 63.3% | 36.7% | D +26.6 | 100.0% | 0.0% | 14.6 to 38.6 | 2 clusters2026-09-21 · J−12 | |
| South Carolina · Regular | D · Annie Andrews | R · Darline Graham | 46.6% | 53.4% | R +6.8 | 17.4% | 82.6% | -18.8 to 5.2 | 7 clusters2026-09-29 · J−4 | |
| South Dakota · Regular | I · Brian Bengs | R · Mike Rounds | 47.5% | 52.5% | R +5.0 | 34.0% | 66.0% | -24.8 to 14.8 | 3 clusters2026-09-27 · J−6 | |
| Tennessee · Regular | D · Marquita Bradshaw | R · Bill Hagerty | 37.4% | 62.6% | R +25.3 | 0.0% | 100.0% | -37.2 to -13.3 | 1 cluster2026-08-26 · J−38 | |
| Texas · Regular | D · James Talarico | R · Ken Paxton | 49.9% | 50.1% | R +0.3 | 48.4% | 51.6% | -12.3 to 11.7 | 27 clusters2026-09-30 · J−3 | |
| Virginia · Regular | D · Mark R. Warner | R · Bert Mizusawa | 60.2% | 39.8% | D +20.4 | 99.7% | 0.3% | 8.5 to 32.4 | 2 clusters2026-06-16 · J−109 | |
| West Virginia · Regular | D · Rachel Fetty Anderson | R · Shelley Moore Capito | 32.4% | 67.6% | R +35.3 | 0.0% | 100.0% | -49.5 to -21.1 | Structure onlyno poll retained | |
| Wyoming · Regular | D · James Byrd | R · Harriet Hageman | 31.2% | 68.8% | R +37.6 | 0.0% | 100.0% | -51.8 to -23.4 | Structure onlyno poll retained |
Show technical layers and detailed filters
THE LOCAL DETAIL
The 35 races
| Race | Opposition / R | Structure | Polls | Center | P(opposition) | P(R) | Latest fieldwork | Coverage |
|---|---|---|---|---|---|---|---|---|
| Alabama · Regular | Everett Wess (D)Barry Moore (R) | -23.41 | -18.99 | -20.93 | 0.2% | 99.8% | 2026-09-25 | Signal ≤45 jours |
| Alaska · Regular | Mary Peltola (D)Dan S. Sullivan (R) | -9.13 | 1.42 | -3.22 | 32.9% | 67.1% | 2026-10-01 | Signal ≤45 jours |
| Arkansas · Regular | Hallie Shoffner (D)Tom Cotton (R) | -25.12 | -5.99 | -14.40 | 2.4% | 97.6% | 2026-08-18 | Signal >45 jours |
| North Carolina · Regular | Roy Cooper (D)Michael Whatley (R) | 17.82 | 9.11 | 12.94 | 96.2% | 3.8% | 2026-09-29 | Signal ≤45 jours |
| South Carolina · Regular | Annie Andrews (D)Darline Graham (R) | -13.00 | -1.96 | -6.82 | 17.4% | 82.6% | 2026-09-29 | Signal ≤45 jours |
| Colorado · Regular | John Hickenlooper (D)Mark Baisley (R) | 22.14 | 13.04 | 17.05 | 99.0% | 1.0% | 2026-07-13 | Signal >45 jours |
| South Dakota · Regular | Brian Bengs (I)Mike Rounds (R) | — | -4.99 | -4.99 | 34.0% | 66.0% | 2026-09-27 | Dedicated I/R aggregate |
| Delaware · Regular | Chris Coons (D)Michael "Dr. Mike" Katz (R) | 25.98 | — | 25.98 | 99.9% | 0.1% | — | Structure only |
| Florida · Special | Angie Nixon (D)Ashley Moody (R) | -10.66 | -4.29 | -7.09 | 16.5% | 83.5% | 2026-09-27 | Signal ≤45 jours |
| Georgia · Regular | Jon Ossoff (D)Mike Collins (R) | 10.36 | 9.18 | 9.70 | 90.9% | 9.1% | 2026-09-23 | Signal ≤45 jours |
| Idaho · Regular | Todd Achilles (I)Jim Risch (R) | — | -14.68 | -14.68 | 11.2% | 88.8% | 2026-09-30 | Dedicated I/R aggregate |
| Illinois · Regular | Juliana Stratton (D)Don Tracy (R) | 12.37 | — | 12.37 | 92.4% | 7.6% | — | Structure only |
| Iowa · Regular | Josh Turek (D)Ashley Hinson (R) | -7.73 | 0.56 | -3.09 | 33.6% | 66.4% | 2026-10-01 | Signal ≤45 jours |
| Kansas · Regular | Adam Hamilton (D)Roger Marshall (R) | -11.90 | 0.06 | -5.21 | 23.7% | 76.3% | 2026-10-01 | Signal ≤45 jours |
| Kentucky · Regular | Charles Booker (D)Andy Barr (R) | -22.93 | -10.11 | -15.75 | 1.5% | 98.5% | 2026-08-27 | Signal ≤45 jours |
| Louisiana · Regular | "Jamie" Davis (D)Julia Letlow (R) | -16.58 | -5.13 | -10.17 | 8.1% | 91.9% | 2026-09-19 | Signal ≤45 jours |
| Maine · Regular | Troy D. Jackson (D)Susan M. Collins (R) | 4.89 | 0.47 | 2.41 | 63.0% | 37.0% | 2026-10-01 | Signal ≤45 jours |
| Massachusetts · Regular | Edward J. Markey (D)John Deaton (R) | 37.25 | 29.80 | 33.08 | 100.0% | 0.0% | 2026-09-22 | Signal ≤45 jours |
| Michigan · Regular | Abdul El-Sayed (D)Mike Rogers (R) | 1.68 | 3.15 | 2.50 | 63.5% | 36.5% | 2026-09-30 | Signal ≤45 jours |
| Minnesota · Regular | Peggy Flanagan (D)Michele Tafoya (R) | 5.85 | 1.99 | 3.68 | 69.4% | 30.6% | 2026-09-29 | Signal ≤45 jours |
| Mississippi · Regular | Scott Colom (D)Cindy Hyde-Smith (R) | -16.57 | -7.31 | -11.39 | 5.9% | 94.1% | 2026-08-15 | Signal >45 jours |
| Montana · Regular | Seth Bodnar (I)Kurt Alme (R) | — | -16.05 | -16.05 | 9.2% | 90.8% | 2026-09-24 | Dedicated I/R aggregate |
| Nebraska · Regular | Dan Osborn (I)Pete Ricketts (R) | — | -2.56 | -2.56 | 41.6% | 58.4% | 2026-09-30 | Dedicated I/R aggregate |
| New Hampshire · Regular | Chris Pappas (D)John E. Sununu (R) | 3.03 | 6.64 | 5.06 | 75.6% | 24.4% | 2026-09-27 | Signal ≤45 jours |
| New Jersey · Regular | Cory Booker (D)Justin Murphy (R) | 19.75 | — | 19.75 | 98.9% | 1.1% | — | Structure only |
| New Mexico · Regular | Ben R. Luján (D)Larry E. Marker (R primary write-in) (R) | 17.74 | 16.48 | 17.04 | 99.0% | 1.0% | 2026-08-28 | Signal ≤45 jours |
| Ohio · Special | Sherrod Brown (D)Jon Husted (R) | -2.32 | 3.97 | 1.20 | 56.5% | 43.5% | 2026-10-01 | Signal ≤45 jours |
| Oklahoma · Regular | N'Kiyla Jasmine Thomas (D)Kevin Hern (R) | -22.69 | -32.43 | -28.14 | 0.0% | 100.0% | 2026-08-06 | Signal >45 jours |
| Oregon · Regular | Jeff Merkley (D)David Brock Smith (R) | 25.63 | — | 25.63 | 99.9% | 0.1% | — | Structure only |
| Rhode Island · Regular | John F. Reed (D)Raymond T. McKay (R) | 29.68 | 24.18 | 26.60 | 100.0% | 0.0% | 2026-09-21 | Signal ≤45 jours |
| Tennessee · Regular | Marquita Bradshaw (D)Bill Hagerty (R) | -24.21 | -26.10 | -25.27 | 0.0% | 100.0% | 2026-08-26 | Signal ≤45 jours |
| Texas · Regular | James Talarico (D)Ken Paxton (R) | -4.04 | 2.64 | -0.30 | 48.4% | 51.6% | 2026-09-30 | Signal ≤45 jours |
| Virginia · Regular | Mark R. Warner (D)Bert Mizusawa (R) | 18.20 | 22.18 | 20.43 | 99.7% | 0.3% | 2026-06-16 | Signal >45 jours |
| West Virginia · Regular | Rachel Fetty Anderson (D)Shelley Moore Capito (R) | -35.28 | — | -35.28 | 0.0% | 100.0% | — | Structure only |
| Wyoming · Regular | James Byrd (D)Harriet Hageman (R) | -37.61 | — | -37.61 | 0.0% | 100.0% | — | Structure only |
RACE-BY-RACE AUDIT
Exact calculation details
Each sheet follows the engine's chain. The numbers come from the calculation of October 3, 2026; this section makes no new estimate.
Alaska · AK-SEN
D · Mary Peltola / R · Dan S. Sullivan · regular election
32.8%P(D) in the modeled pair
01 · Structure VNext
structure = state presidential result (H1) + gap of the seat’s last election (H2−H1) + candidate block (incumbent, open seat, former senator, governor) + Generic Ballot × state elasticity
Structure-9.135 ptsGeneric Ballot of the structure6.90 pts, 16 SeptemberFinanceExcluded: undated FEC historiesEconomy, approvalNot included (to be measured)
02 · Structure status
Value read from the Common State engine; the variable-by-variable breakdown remains in the engine package.
RouteFULL_FIELD_BOUNDED_RCVScope of the probabilitiesPAIR_PROBABILITY_EQUALS_FULL_OUTCOME_WITHIN_BOUND
03 · Polls and blend
center = 0.56 × polls + 0.44 × structure
Raw aggregate1.421 ptsConditional aggregate1.421 ptsClusters10Primary clustersNot measuredLatest fieldwork2026-10-01AgeJ−2Posterior center-3.223 pts
04 · Uncertainty
marginal σ = √(national σ² + state σ² + race σ²); national shock common to the D/R axes only
σ national1.830state σ0.000σ race7.044σ marginal7.278Interval 90%-15.19 to 8.75 pts
05 · Probability
Analytic P(opposition) = Φ(center / marginal σ); Monte-Carlo = frequency of margin > 0 out of 200,000 draws
P analytique32.89%P Monte-Carlo32.84%MC − analytic gap-0.051 ptP(R) Monte-Carlo67.16%
06 · Reading the center
Central D score48.39%Central R score51.61%MarginR +3.22 ptsP(autre)Not modeled / NON_MESURE
Quality flags
FULL_FIELD_BOUNDED_RCVPOLL_SOURCES_SECONDARY_PRIMARY_NOT_REVERIFIED
Run SENATE-COMMON-STATE-POLL-REFRESH-20261003. Probabilities conditional on the modeled pair; this is not a scientific certification.
METHOD & TRACEABILITY
How the forecast is built
VNext model: state presidential divergence from the seat's last election candidate block Generic Ballot × elasticity. Finance excluded as long as the histories are undated.
Aggregate J47_A: half-life of 14 days weight √n one group per pollster and per date. Blend of 56% polls and 44% structure. Without polls structure alone.
Common national shock of 1 83 point on the D/R axes race-specific residual. The three I/R races do not receive the national shock.
200,000 draws. The independents' caucus scenarios are assumptions with no probability of their own.
DOCUMENTED HISTORICAL TESTS
What the model showed on past elections
MAE and RMSE in margin points. Past errors do not guarantee the accuracy of 2026.
Visible limits: probabilities conditional on the modelled duel; other candidates bounded by the polls, without simulating their score; polls from secondary sources; structure set on the 16 September Generic Ballot.
A provisional forecast. Not a certification.
Outputs are recomputed every day. Primary verification of the polls and the link between House, Senate and governors remain open: control of both chambers is given as an exact range on the overview page, not as a single figure.
UPDATES & TRACEABILITY
A page linked to its calculation
As a local file, the embedded snapshot is the source of truth. Over HTTP(S), the button only checks a possible feed senate-engine-page-data.json after validation; it never silently replaces the displayed calculation.
DOCUMENTATION
Sources, files and reference dates
Deduplicated list of references and provenance leads already archived in the race sheets. A text string is not turned into a verified URL.
forecast_us_2026.jsonSENATE-COMMON-STATE-POLL-REFRESH-20261003
SENATE_COMMON_STATE_INTEGRATION_V1Structure VNext · J47_A · blend 0.56
Wikipedia, Decision Desk HQ and cited pollsters
through 2026-10-03