MA · Senate 2026 · Updated Oct 28, 2026, 2:01 a.m. ET
Massachusetts
Rated Solid D
Ed Markey wins this seat in >99 in 100 simulations. Call it all but certain.
Ed MarkeyDIncumbent>99 in 100- John DeatonR<1 in 100
Over time
How the forecast has moved
The margin
How close it lands
Each simulation produces a final margin. The curve shows where those margins fall; the tinted areas on either side of even are the futures each party wins.
Under the hood
What's driving the number
The forecast blends a weighted poll average with a fundamentals model: the state's partisan lean, incumbency, the national environment, and fundraising. Positive points favor the Democratic side of the margin; negative favor the Republican side.
- Partisan leanD +27.3
- IncumbencyD +2.5
- National environmentD +4.7
- FundraisingD +1.1
- Fundamentals sayD +35.5
- The polls sayD +29.1
- Blended forecast marginD +31.8
The blend puts 58 percent of its weight on the polls and 42 percent on the fundamentals; polls take over as more arrive and election day nears.
The field
How other forecasters see this race
Ours isn't the only model on this race. Where another forecaster publishes a number — or we've copied one in by hand from a paywalled model — it appears here beside ours, dated, because models update on their own schedules. Forecasts disagree for knowable reasons: different poll filters, different weights on the fundamentals, different priors.
- Ed Markey winsThis forecast>99 in 100
- Ed Markey winsRametta & Hare · as of Oct 27100 in 100
No model is "right" before the votes are counted. How our number is made — and how it scored against 2012–2024 races — is on the methodology page.
The markets
What the betting markets say
Prediction markets put a price on this seat too: what people are paying for a contract that pays out if Ed Markey wins, read as an implied probability. Shown for comparison only. This is not betting advice, and market prices never feed the model.
- Ed Markey winsThis forecast>99 in 100
- Ed Markey winsKalshi98 in 100
- Ed Markey winsPolymarket99 in 100
Market prices as of Oct 28, 2026, 2:00 a.m. ET
The evidence
The polls, as the model sees them
Every public poll of this race, with the weight the model gave it in the latest run. Weights reward recency, sample size, and pollster track record; the house adjustment corrects each pollster's habitual lean before averaging.
| Poll | Dates | Sample | D–R | Margin | House adj. | Weight |
|---|---|---|---|---|---|---|
| Suffolk University | Oct 14–18 | 500 LV | 60–32 | D +28.0 | +1.5 | 61% |
| UMass Amherst / YouGov | Oct 5–12 | 800 RV | 54–28 | D +26.0 | — | 22% |
| MassINC Polling Group | Sep 14–22 | 800 LV | 52–26 | D +26.0 | +0.6 | 11% |
| University of New Hampshire | Sep 17–21 | 564 LV | 53–30 | D +23.0 | −0.1 | 5% |
| University of New Hampshire | Aug 20–24 | 881 LV | 49–30 | D +19.0 | −0.1 | <1% |
| UMass Amherst / YouGov | Aug 5–12 | 800 RV | 51–30 | D +21.0 | — | <1% |
| University of New Hampshire | Jun 18–23 | 623 LV | 50–34 | D +16.0 | −0.1 | <1% |
| Suffolk University | Jun 8–12 | 500 LV | 55–30 | D +25.0 | +1.5 | <1% |
| University of New Hampshire | Apr 16–20 | 603 LV | 55–32 | D +23.0 | −0.1 | <1% |
| University of New Hampshire | Feb 12–16 | 620 LV | 56–27 | D +29.0 | −0.1 | 0% |
| Cygnal (R) | Jan 22–25 | 800 LV | 54–30 | D +24.0 | +1.5 | 0% |
| Suffolk University | Nov 19–23 | 500 RV | 54–31 | D +23.0 | +1.5 | 0% |
| SurveyUSA | Feb 28–Mar 4 | 775 RV | 45–26 | D +19.0 | +1.9 | 0% |
How the weights, the blend, and the simulation work is spelled out on the methodology page.