Races · Senate · 2026 · MA

Senate · class II · open seat

Ed Markey vs John Deaton

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Safe D D +27.0 · 176 days to election · 10 polls · 4 markets Last poll 20d ago Markets 4d ago Rating 1d ago

Where this race stands

Verified

Safe D · model 99% D

safe-d · trending-r · uncertainty-high

Forecast · poliagg-v8

Predicted final margin

D +32.3

80% CI: D +14.7 → D +49.8 · win prob 99%

R+30R+15TIEDD+15D+30

Quality · inputs

Data quality · medium

Polls used	10
Days to election	181
Residual σ	13.66pt
Generated	5/6/2026

▼ Compare with other models3 models

qgbt-v1GBT (qgbt)

D +26.8

80% CI D +12.7 → D +29.0

CV MAE 7.21

bayes-v1Bayes / Kalman

D +23.0

80% CI D +21.4 → D +24.7

CV MAE 1.30

poliagg-v8Ensemble (production)

D +32.3

80% CI D +14.7 → D +49.8

CV MAE 13.66

Polling average

Simple Weighted House-corrected Trimmed LOESS Kalman

Method:Weighted, plus each pollster's measured bias subtracted before averaging.

Show poll dots95% CI bandOverlay all methods|Toggle:

All polls · 10 results

Pollster:Population:Lean:High-quality only (weight ≥ 1.5)Sort:10 of 10 polls

End	Pollster	Weight	Lean	Sample	MoE	Pop	Trust signals	Results	Source
4/20/2026	University of New Hampshire	1.00	—(R+0.9)	603	±4.0	LV	high variance vs editorial consensus✓ verified 5d ago+2 high variance vs editorial consensus Stdev of (poll − rater consensus) across 50 historical paired polls exceeds 8pt — this pollster's results swing widely relative to where the editors place the same races. ✓ verified 5d ago auto-checked on 5/4/2026. Deterministic checks confirmed bounds + structure (percentages in [0,100], totals plausibly close to 100%, dates ordered). Source page itself was not re-fetched. likely-voter screen Likely-voter screen — pollster filters respondents by reported turnout intent. Generally tighter for predicting elections than registered- or adult-population polls. bias R+0.9pt Across 12 historical scored polls the average error vs. actual margin is R+0.9pt.	Ed Markey 55.0 · John Deaton 32.0	poll arch
4/20/2026	University of New Hampshire	1.00	—(R+0.9)	600	±4.0	LV	high variance vs editorial consensus✓ verified 5d ago+2 high variance vs editorial consensus Stdev of (poll − rater consensus) across 50 historical paired polls exceeds 8pt — this pollster's results swing widely relative to where the editors place the same races. ✓ verified 5d ago auto-checked on 5/4/2026. Deterministic checks confirmed bounds + structure (percentages in [0,100], totals plausibly close to 100%, dates ordered). Source page itself was not re-fetched. likely-voter screen Likely-voter screen — pollster filters respondents by reported turnout intent. Generally tighter for predicting elections than registered- or adult-population polls. bias R+0.9pt Across 12 historical scored polls the average error vs. actual margin is R+0.9pt.	Seth Moulton 56.0 · John Deaton 25.0	poll arch
2/16/2026	University of New Hampshire	1.00	—(R+0.9)	620	±3.9	LV	83d oldhigh variance vs editorial consensus+3 83d old Poll was fielded 83 days ago. Older polls reflect an earlier state of the race and are weighted down in the rolling average. high variance vs editorial consensus Stdev of (poll − rater consensus) across 50 historical paired polls exceeds 8pt — this pollster's results swing widely relative to where the editors place the same races. ✓ verified 5d ago auto-checked on 5/4/2026. Deterministic checks confirmed bounds + structure (percentages in [0,100], totals plausibly close to 100%, dates ordered). Source page itself was not re-fetched. likely-voter screen Likely-voter screen — pollster filters respondents by reported turnout intent. Generally tighter for predicting elections than registered- or adult-population polls. bias R+0.9pt Across 12 historical scored polls the average error vs. actual margin is R+0.9pt.	Ed Markey 56.0 · John Deaton 27.0	poll arch
2/16/2026	University of New Hampshire	1.00	—(R+0.9)	620	±3.9	LV	83d oldhigh variance vs editorial consensus+3 83d old Poll was fielded 83 days ago. Older polls reflect an earlier state of the race and are weighted down in the rolling average. high variance vs editorial consensus Stdev of (poll − rater consensus) across 50 historical paired polls exceeds 8pt — this pollster's results swing widely relative to where the editors place the same races. ✓ verified 5d ago auto-checked on 5/4/2026. Deterministic checks confirmed bounds + structure (percentages in [0,100], totals plausibly close to 100%, dates ordered). Source page itself was not re-fetched. likely-voter screen Likely-voter screen — pollster filters respondents by reported turnout intent. Generally tighter for predicting elections than registered- or adult-population polls. bias R+0.9pt Across 12 historical scored polls the average error vs. actual margin is R+0.9pt.	Seth Moulton 59.0 · John Deaton 23.0	poll arch
1/25/2026	Cygnal	1.04	R(D+1.8)	800	±3.5	LV	commissioned by R-aligned: Internal R-aligned105d old+3 commissioned by R-aligned: Internal R-aligned This poll was commissioned by a Republican-aligned committee, party, or PAC (Internal R-aligned). Such polls historically lean toward their sponsor. 105d old Poll was fielded 105 days ago. Older polls reflect an earlier state of the race and are weighted down in the rolling average. ✓ verified 5d ago auto-checked on 5/4/2026. Deterministic checks confirmed bounds + structure (percentages in [0,100], totals plausibly close to 100%, dates ordered). Source page itself was not re-fetched. likely-voter screen Likely-voter screen — pollster filters respondents by reported turnout intent. Generally tighter for predicting elections than registered- or adult-population polls. tracks editorial consensus Across 72 historical paired polls, this pollster's D-margins track the rater consensus (Cook / Sabato / IE / 538 / DDHQ etc.) with high correlation (r ≥ 0.85) and small mean delta (\|Δ\| ≤ 2pt). Their results align with conventional wisdom.	Ed Markey 54.0 · John Deaton 30.0	poll arch
11/23/2025	Suffolk University	1.44	neutral(D+0.1)	500	±4.4	RV	168d old✓ verified 5d ago+3 168d old Poll was fielded 168 days ago. Older polls reflect an earlier state of the race and are weighted down in the rolling average. ✓ verified 5d ago auto-checked on 5/4/2026. Deterministic checks confirmed bounds + structure (percentages in [0,100], totals plausibly close to 100%, dates ordered). Source page itself was not re-fetched. registered voters Registered-voter sample — broader than likely-voter screens; typical for early-cycle polling before turnout signals stabilize. bias D+0.1pt Across 15 historical scored polls the average error vs. actual margin is D+0.1pt. tracks editorial consensus Across 55 historical paired polls, this pollster's D-margins track the rater consensus (Cook / Sabato / IE / 538 / DDHQ etc.) with high correlation (r ≥ 0.85) and small mean delta (\|Δ\| ≤ 2pt). Their results align with conventional wisdom.	Ed Markey 54.0 · John Deaton 31.0	poll arch
11/23/2025	Suffolk University	1.44	neutral(D+0.1)	500	±4.4	RV	168d old✓ verified 5d ago+3 168d old Poll was fielded 168 days ago. Older polls reflect an earlier state of the race and are weighted down in the rolling average. ✓ verified 5d ago auto-checked on 5/4/2026. Deterministic checks confirmed bounds + structure (percentages in [0,100], totals plausibly close to 100%, dates ordered). Source page itself was not re-fetched. registered voters Registered-voter sample — broader than likely-voter screens; typical for early-cycle polling before turnout signals stabilize. bias D+0.1pt Across 15 historical scored polls the average error vs. actual margin is D+0.1pt. tracks editorial consensus Across 55 historical paired polls, this pollster's D-margins track the rater consensus (Cook / Sabato / IE / 538 / DDHQ etc.) with high correlation (r ≥ 0.85) and small mean delta (\|Δ\| ≤ 2pt). Their results align with conventional wisdom.	Seth Moulton 52.0 · John Deaton 29.0	poll arch
3/4/2025	SurveyUSA	1.00	—(D+1.5)	775	—	RV	432d old✓ verified 5d ago+2 432d old Poll was fielded 432 days ago. Older polls reflect an earlier state of the race and are weighted down in the rolling average. ✓ verified 5d ago auto-checked on 5/4/2026. Deterministic checks confirmed bounds + structure (percentages in [0,100], totals plausibly close to 100%, dates ordered). Source page itself was not re-fetched. registered voters Registered-voter sample — broader than likely-voter screens; typical for early-cycle polling before turnout signals stabilize. tracks editorial consensus Across 73 historical paired polls, this pollster's D-margins track the rater consensus (Cook / Sabato / IE / 538 / DDHQ etc.) with high correlation (r ≥ 0.85) and small mean delta (\|Δ\| ≤ 2pt). Their results align with conventional wisdom.	Ed Markey 45.0 · John Deaton 26.0	poll arch
2/20/2025	UMass Amherst/YouGov	1.00	—	700	±4.8	A	flagged on verificationno scored polls+2 flagged on verification Automated verification flagged this poll: results sum to 68.0% (expected ~100; n=2 cands, floor=70). Either the scrape misread the source table or the source itself looks unusual. Cross-check the citation URL before relying on this row. no scored polls Pollster has no historical polls with a known outcome in our database, so accuracy and bias cannot be measured. adult sample Adult-population sample (no voter screen) — useful for general public opinion but not directly comparable to LV polls for predicting elections. 444d old Poll was fielded 444 days ago. Older polls reflect an earlier state of the race and are weighted down in the rolling average.	Ed Markey 35.0 · Charlie Baker 33.0	poll arch
11/1/2024	MassINC Polling Group	1.00	—	582	±4.9	LV	no scored polls555d old+2 no scored polls Pollster has no historical polls with a known outcome in our database, so accuracy and bias cannot be measured. 555d old Poll was fielded 555 days ago. Older polls reflect an earlier state of the race and are weighted down in the rolling average. ✓ verified 5d ago auto-checked on 5/4/2026. Deterministic checks confirmed bounds + structure (percentages in [0,100], totals plausibly close to 100%, dates ordered). Source page itself was not re-fetched. likely-voter screen Likely-voter screen — pollster filters respondents by reported turnout intent. Generally tighter for predicting elections than registered- or adult-population polls.	Ed Markey 34.0 · Charlie Baker 40.0	poll arch

Trust signals are deterministic flags computed from the pollster scorecard (track-record size, historical bias, aggregation weight) and the poll itself (sample size, population, age, citation availability). No interpretation; click any row to see the cited numbers behind each flag.

Editorial ratings · poll-vs-rater

3 raters

Rater	Rating	Updated	Poll D-marg.	Rater marg.	Δ poll−rater
The Cook Political Report	Safe D	Oct 14	+27.0	+18.0	+9.0
Inside Elections	Safe D	Aug 12	+27.0	+18.0	+9.0
Sabato's Crystal Ball	Safe D	Aug 12	+27.0	+18.0	+9.0

Δ POLL−RATER = polling-consensus margin minus the rater's implied bucket midpoint. Positive = polls more D than rater; negative = rater more D than polls. |Δ| < 0.6 well-aligned · 0.6–1.5 mild divergence · ≥1.5 contested call.

last poll 3 weeks ago (4/20/2026) last market quote 4 days ago rating computed 1 day ago

Rating history (1 change)