US 2026 Congress and Senate Projections
BUNKER Political Intelligence | Public Forecast Report
1 Executive Control Dashboard
1.1 📋 Strategic Analytical Brief & Insights
- The balance-of-power baseline has shifted since June.
The June public report centered on a divided-government configuration: 52 GOP / 48 DEM in the Senate and 230 DEM / 205 GOP in the House. The current forecast centers on 51 D/aligned / 49 R in the Senate and 226 D / 209 R in the House. In the paired chamber simulation, Democratic control of both chambers is currently the single largest joint outcome at 52.4%. - The Senate battlefield has moved through the former GOP firewall.
In June, Alaska, Ohio, Texas, Iowa, Montana and Nebraska sat inside a Republican-leaning firewall, North Carolina carried a competitive GOP edge, Michigan was near the tipping point and Georgia leaned Democratic. Today the official forecast places Texas at 50.2% D vote / 52.6% P(D win) and Ohio at 50.1% / 50.7%, while Alaska remains nearly even at 49.7% / 47.0%. Iowa and Montana remain on the Republican side; North Carolina, Michigan and Georgia have moved deeper into the Democratic side of the current model. - The House has a meaningful structural cushion even inside the closest races.
The House center has moved from 230 D / 205 R in the June report to 226 D / 209 R today, with 82.6% modeled probability of Democratic control. BUNKER currently classifies 12 districts inside the Pure Toss-Up band (49.5%–50.5% expected Democratic vote). Even if Republicans swept all 12 of those contests, the official district-call arithmetic would still leave Democrats at 221 seats versus 214 Republicans—above the 218-seat majority threshold. Republicans would still need to flip at least 4 additional Democratic-projected districts outside the Pure Toss-Up band to take control. The 85% interval of 213–239 Democratic seats still crosses 218, so the majority is favored rather than guaranteed. - A blue-wave configuration is now a live upside scenario, not the base-case label.
The current central forecast already places both chambers on the Democratic side of their control thresholds. A uniform pro-Democratic shift of only about 0.29 points across current race centers would move the Senate center to at least 52 D/aligned seats; under the same stress the House center would broaden further. This is a conditional stress scenario—not a declaration that a wave will occur—but it shows that continued movement in the present direction would expand the upper Democratic tail. - The Senate remains the first control point to break under a counter-shock.
In a uniform vote-share stress applied to current race centers, roughly a 0.07-point Republican shift is enough to move the Senate central count below the 51-seat Democratic control threshold. The House central count does not fall below 218 Democratic seats until roughly a 1.56-point Republican shift. The result is a materially narrower Senate control margin than the House margin.
June comparison note: the prior-report values are used as a descriptive reference. The production architecture has been upgraded since June, so the change should not be interpreted as a pure same-model time series.
2 U.S. Senate Analysis
The current Senate forecast centers on 51 D/aligned seats and 49 Republican seats, with 60.1% probability of Democratic control. The 85% modeled range is 48–55 D/aligned seats. The public focus below is the final forecast and how the battleground has evolved—not the internal mechanics used to build it.
2.1 Battlefield Evolution Since the June Report
| State | June public-report position | Current projected DEM/aligned vote | Current P(DEM/aligned wins) | Current tier | Official projection |
|---|---|---|---|---|---|
| NE | Lean GOP | 39.8% | 3.3% | Solid REP | REP |
| AK | Lean GOP | 49.7% | 47.0% | Pure Toss-Up | REP |
| OH | Lean GOP | 50.1% | 50.7% | Pure Toss-Up | DEM |
| TX | Lean GOP | 50.2% | 52.6% | Pure Toss-Up | DEM |
| IA | Lean GOP | 49.5% | 44.7% | Pure Toss-Up | REP |
| MT | Lean GOP | 47.3% | 31.6% | Lean REP | REP |
| NC | Competitive / GOP edge | 55.8% | 93.9% | Solid DEM | DEM |
| MI | 50/50 tipping edge | 52.8% | 77.5% | Lean DEM | DEM |
| GA | Tilt DEM | 58.2% | 98.6% | Solid DEM | DEM |
The largest structural changes are in Texas and Ohio, which have crossed from the June Republican-leaning firewall to narrow Democratic advantages in the current forecast. Alaska and Texas are effectively centered at the toss-up boundary, Iowa remains narrowly Republican, and the Democratic side is stronger in Michigan, North Carolina and Georgia than it was in the June narrative.
2.2 Geographic Map of the 35 Senate Contests
2.3 State-Level Projection Table for the 35 Senate Contests
| State | Projected DEM/aligned vote | Projected REP vote | P(DEM/aligned wins) | P(REP wins) | IC85 projected DEM/aligned vote | Official projection | Competitiveness tier |
|---|---|---|---|---|---|---|---|
| South Dakota (SD) | 31.5% | 68.5% | 0.0% | 100.0% | 23.5–39.5% | REP | Solid REP |
| West Virginia (WV) | 31.7% | 68.3% | 0.1% | 99.9% | 23.7–39.7% | REP | Solid REP |
| Wyoming (WY) | 33.1% | 66.9% | 0.1% | 99.9% | 25.1–41.1% | REP | Solid REP |
| Idaho (ID) | 33.9% | 66.1% | 0.2% | 99.8% | 25.9–41.9% | REP | Solid REP |
| Tennessee (TN) | 37.8% | 62.2% | 1.4% | 98.6% | 29.8–45.8% | REP | Solid REP |
| Kentucky (KY) | 42.1% | 57.9% | 1.8% | 98.2% | 36.7–47.5% | REP | Solid REP |
| Kansas (KS) | 42.4% | 57.6% | 2.7% | 97.3% | 36.7–48.1% | REP | Solid REP |
| Nebraska (NE) | 39.8% | 60.2% | 3.3% | 96.7% | 31.8–47.8% | REP | Solid REP |
| Louisiana (LA) | 43.4% | 56.6% | 3.8% | 96.2% | 38.0–48.7% | REP | Solid REP |
| Florida (FL) | 41.2% | 58.8% | 5.6% | 94.4% | 33.2–49.2% | REP | Solid REP |
| Mississippi (MS) | 42.0% | 58.0% | 7.6% | 92.4% | 34.0–50.0% | REP | Solid REP |
| Oklahoma (OK) | 42.3% | 57.7% | 8.3% | 91.7% | 34.3–50.3% | REP | Solid REP |
| Arkansas (AR) | 41.6% | 58.4% | 14.7% | 85.3% | 30.0–53.1% | REP | Solid REP |
| Alabama (AL) | 44.2% | 55.8% | 14.9% | 85.1% | 36.2–52.2% | REP | Solid REP |
| South Carolina (SC) | 44.2% | 55.8% | 21.6% | 78.4% | 33.5–54.9% | REP | Solid REP |
| Montana (MT) | 47.3% | 52.7% | 31.6% | 68.4% | 39.3–55.3% | REP | Lean REP |
| Iowa (IA) | 49.5% | 50.5% | 44.7% | 55.3% | 44.1–54.9% | REP | Pure Toss-Up |
| Alaska (AK) | 49.7% | 50.3% | 47.0% | 53.0% | 44.3–55.1% | REP | Pure Toss-Up |
| Ohio (OH) | 50.1% | 49.9% | 50.7% | 49.3% | 44.7–55.4% | DEM | Pure Toss-Up |
| Texas (TX) | 50.2% | 49.8% | 52.6% | 47.4% | 44.9–55.6% | DEM | Pure Toss-Up |
| Maine (ME) | 51.6% | 48.4% | 66.4% | 33.6% | 46.2–57.0% | DEM | Lean DEM |
| Michigan (MI) | 52.8% | 47.2% | 77.5% | 22.5% | 47.4–58.2% | DEM | Lean DEM |
| New Hampshire (NH) | 55.4% | 44.6% | 92.4% | 7.6% | 50.0–60.7% | DEM | Solid DEM |
| North Carolina (NC) | 55.8% | 44.2% | 93.9% | 6.1% | 50.4–61.2% | DEM | Solid DEM |
| New Jersey (NJ) | 58.7% | 41.3% | 94.1% | 5.9% | 50.7–66.7% | DEM | Solid DEM |
| Delaware (DE) | 59.2% | 40.8% | 95.1% | 4.9% | 51.2–67.2% | DEM | Solid DEM |
| New Mexico (NM) | 59.8% | 40.2% | 96.1% | 3.9% | 51.8–67.8% | DEM | Solid DEM |
| Minnesota (MN) | 56.8% | 43.2% | 96.5% | 3.5% | 51.4–62.2% | DEM | Solid DEM |
| Illinois (IL) | 60.8% | 39.2% | 97.4% | 2.6% | 52.8–68.8% | DEM | Solid DEM |
| Virginia (VA) | 61.9% | 38.1% | 98.4% | 1.6% | 53.9–69.9% | DEM | Solid DEM |
| Georgia (GA) | 58.2% | 41.8% | 98.6% | 1.4% | 52.8–63.6% | DEM | Solid DEM |
| Colorado (CO) | 62.8% | 37.2% | 98.9% | 1.1% | 54.8–70.8% | DEM | Solid DEM |
| Oregon (OR) | 65.1% | 34.9% | 99.7% | 0.3% | 57.1–73.1% | DEM | Solid DEM |
| Rhode Island (RI) | 65.7% | 34.3% | 99.8% | 0.2% | 57.7–73.7% | DEM | Solid DEM |
| Massachusetts (MA) | 66.2% | 33.8% | 99.8% | 0.2% | 58.2–74.2% | DEM | Solid DEM |
For Nebraska only, the Democratic-aligned opposition slot can correspond to an Independent candidacy under the seat-control convention; when that slot is projected to win, the public label is shown as IND rather than DEM.
2.4 Matrix of the 35 Contests — Projected Competitiveness
2.5 Where Markets and the Model Diverge Most
| State | Projected DEM/aligned vote | BUNKER P(DEM/aligned wins) | Market P(DEM) | Market source | Market − BUNKER probability gap | Official projection |
|---|---|---|---|---|---|---|
| MT | 47.3% | 31.6% | 1.0% | Market source not recorded | -30.6 pp | REP |
| AK | 49.7% | 47.0% | 68.0% | Market source not recorded | +21.0 pp | REP |
| MI | 52.8% | 77.5% | 65.5% | Market source not recorded | -12.0 pp | DEM |
| NH | 55.4% | 92.4% | 83.5% | Market source not recorded | -8.9 pp | DEM |
| TX | 50.2% | 52.6% | 58.5% | Market source not recorded | +5.9 pp | DEM |
| GA | 58.2% | 98.6% | 93.0% | Market source not recorded | -5.6 pp | DEM |
| IA | 49.5% | 44.7% | 39.5% | Market source not recorded | -5.2 pp | REP |
| ME | 51.6% | 66.4% | 70.5% | Market source not recorded | +4.1 pp | DEM |
| MN | 56.8% | 96.5% | 92.5% | Market source not recorded | -4.0 pp | DEM |
| OH | 50.1% | 50.7% | 54.5% | Market source not recorded | +3.8 pp | DEM |
This table is included because disagreement can be informative. It shows where public betting-market expectations differ most from BUNKER’s current probability estimate. The market number is not a second projection and does not replace the official forecast shown above.
3 U.S. House of Representatives Analysis
The House forecast centers on 226 Democratic seats and 209 Republican seats, with 82.6% probability of Democratic control and an 85% modeled range of 213–239 Democratic seats. The June public report centered on 230 D / 205 R; the current center is four Democratic seats lower, but the present distribution is more concentrated on the Democratic side of the 218-seat threshold than the June report’s 35.3% GOP-majority estimate.
3.1 State Map of District-Level Projections
3.2 Territorial Matrix of All 435 Districts
3.3 House Competitiveness — Official Projection by Tier
| Classification | Expected Democratic vote |
|---|---|
| Solid GOP | Below 45.0% |
| Likely GOP | 45.0% to below 47.0% |
| Lean GOP | 47.0% to below 48.5% |
| Tilt GOP | 48.5% to below 49.5% |
| Pure Toss-Up | 49.5% to below 50.5% |
| Tilt DEM | 50.5% to below 51.5% |
| Lean DEM | 51.5% to below 53.0% |
| Likely DEM | 53.0% to below 55.0% |
| Solid DEM | 55.0% or higher |
These are BUNKER presentation bands applied to the official expected Democratic vote; they are not external race ratings.
4 Balance of Power & Uncertainty
4.1 Chamber Seat Distributions
4.2 Interdependence and Balance of Power
| Balance-of-power outcome | Joint probability |
|---|---|
| Democratic control of both chambers | 52.4% |
| Democratic House / non-Democratic Senate | 30.2% |
| Republican House / Democratic Senate | 7.7% |
| Republican House / non-Democratic Senate | 9.6% |
The joint distribution preserves a common national shock across both chambers. It is intended to show how control outcomes move together, not to create a separate race-level forecast.
4.3 Empirical Core: Intervals and Risk Boundaries
| Chamber | Median | Empirical core (P25–P75) | Risk boundary (P10–P90) | Tail boundary (P2.5–P97.5) | Control threshold |
|---|---|---|---|---|---|
| House of Representatives | 226 seats | 220–232 seats | 214–238 seats | 208–244 seats | 218 seats |
| Senate | 51 seats | 50–53 seats | 48–54 seats | 46–56 seats | 51 seats |
5 Projected Voter Turnout — 2026
Turnout is a structural condition of the 2026 environment, not a partisan prediction by itself. The figures below place BUNKER’s turnout forecast in historical midterm context and then show how that participation environment is distributed across states and the most competitive congressional terrain.
5.1 Historical National Midterm Turnout and 2026 Forecast
BUNKER’s current 50-state VEP-weighted turnout forecast is 47.3%, with an empirical 80% predictive bracket of 43.6–50.4%. The weighting is national in the sense relevant for the state model: each state’s projected turnout is weighted by its share of the voting-eligible population rather than giving small and large states equal influence. Because 2026 VEP is not yet observable and the operational VEP_STATE_2026 vector was not persisted numerically in the recovered turnout artifacts, this public aggregation uses 2024 state VEP — the latest observed Election Lab state weights — as the transparent weighting vintage rather than silently substituting VAP or CVAP.
Higher turnout does not mechanically imply a better result for either party. Its value here is to show whether the 2026 forecast is being generated in a historically low-, normal-, or high-participation midterm environment before examining where participation is concentrated.
5.2 State-Level 2026 Turnout Map
The state map shows why a national average is only the starting point: the modeled participation environment varies materially across the country. Those differences matter most where control is being decided at the margin.
5.3 Turnout in Competitive Senate States
This comparison focuses on the states carrying the greatest leverage in the current Senate control distribution. It is intended to show the participation environment around the battleground, not to imply that turnout by itself determines the winner.
5.4 Turnout Across Competitive House Districts
The district chart shows all 12 Pure Toss-Up districts and deliberately uses a relative turnout index rather than presenting a fabricated district VEP percentage. A value above 100 means the district is projected to participate more strongly than its state’s CVAP-weighted district average; below 100 means the opposite. This lets the public see where turnout intensity may reinforce or weaken the most competitive House terrain without mixing incompatible denominators.
6 Model Validation & Diagnostic Metrics
The public validation answers one question for each chamber: how often did the final forecast call the race correctly when applied to historical elections under forecast-valid rules? Component-model scores are intentionally excluded here; those belong in the internal technical report.
6.1 Historical Backtesting Validation Report
6.1.1 House Historical Forecast Accuracy
|Metric | Result |
|:----------------------------|:---------:|
|Historical races tested | 2,722 |
|Correct final projections | 2,592 |
|Final-forecast call accuracy | 95.2% |
|Validation span | 2012–2024 |
Across the 2012–2024 historical validation window, the final House forecast correctly called 2,592 of 2,722 district races — 95.2%. The chart shows both each election’s realized accuracy and the expanding-window accuracy of the same final forecast through time.
6.1.2 Senate Historical Forecast Accuracy
|Metric | Result |
|:----------------------------|:---------:|
|Historical races tested | 241 |
|Correct final projections | 223 |
|Final-forecast call accuracy | 92.5% |
|Validation span | 2012–2024 |
Across the 2012–2024 historical validation window, the final Senate forecast correctly called 223 of 241 races — 92.5%. This is the end-to-end public accuracy measure for the Senate forecast; the report does not mix it with component-model accuracy rates.
6.2 Monte Carlo Stability
| Chamber | Simulations | Full-run P(DEM control) | Monte Carlo SE | Batch probability range |
|---|---|---|---|---|
| House | 2 million | 82.6% | 0.027 pp | 81.9%–83.5% |
| Senate | 2 million | 60.1% | 0.035 pp | 59.3%–60.8% |
6.3 Stability Curve
6.4 Uniform District-Center Vote-Shift Stress Test
This stress test asks a simple counterfactual question: how far would the current expected-vote centers have to move uniformly toward either party before the central seat count changes control? For the House, the exercise applies the same vote shift to all 435 district expected-vote centers and then recounts which side is above 50% in each district. For the Senate, the same uniform shift is applied to the current state-race centers and the central seat count is recomputed. The horizontal axis therefore represents a uniform movement in race-level vote centers; it is not a generic-ballot estimate and it is not a probability forecast.
In the House, the first Republican-side control boundary appears at roughly a 1.56-point uniform shift. At that point, enough Democratic-projected districts cross below 50% for the central seat count to fall below the 218-seat majority threshold. This is broader than a sweep of the 12 Pure Toss-Up districts: if Republicans won all 12, Democrats would still hold 221 seats to 214 Republican seats, because only 5 of those 12 are currently Democratic calls. Republicans would still need at least 4 additional Democratic-projected districts outside the Pure Toss-Up band to take control. The uniform-shift exercise reaches those additional districts as well.
For the Senate, the current central majority is lost after roughly a 0.07-point Republican shift, while about a 0.29-point Democratic shift moves the central projection to at least 52 Democratic/aligned seats. These thresholds measure sensitivity around the current forecast, not the probability that such a national shift will occur.
6.5 Current Forecast Coverage
| Check | Result | Status |
|---|---|---|
| House district coverage | 435 of 435 | PASS |
| Senate race coverage | 35 of 35 | PASS |
7 Methodology
BUNKER’s 2026 congressional forecast is a hybrid probabilistic model. It combines long-run electoral fundamentals built from historical election, demographic and economic information spanning 1966–2026, current candidate and race polling, and prediction-market information. Those race-level forecasts are then translated into chamber-level uncertainty with 2,000,000 correlated Monte Carlo simulations, allowing national conditions to affect both chambers simultaneously.
The public report deliberately shows the official forecast, uncertainty and validation evidence rather than the internal sequence of model components. Detailed model diagnostics, source-level QA, calibration locks and reproducibility controls remain in BUNKER’s technical internal report.