Senate · 2026

Massachusetts Senate

Ed Markey (D)v.John Deaton (R)SAFE D

Incumbent: Ed Markey, currently Democratic.

Projected margin

D+26.2

Nine in ten outcomes: D+36 to D+17

Chance of winning

>99%

Ed Markey

Polls alone

D+20.6

8 polls from 4 pollsters; latest Aug 24. Weight in projection: 38%.

Fundamentals alone

D+29.6

Weight in projection: 62%.

Polls

The average over time

Each poll is first shifted by its sponsor's and its pollster's measured lean, then weighted by recency and track record. Sample size gets no weight: in 2,000-plus past races it predicted nothing about accuracy. Why.

adjusted weighted average shading: which side the average favors each poll, as published party-aligned pollster or sponsor

Before any poll

What the fundamentals say

A regression on past Senate races, fit without looking at this year. The national environment term uses the generic ballot after its historical correction (D+5.3).

What each term adds to the estimate

BaselineD+0.5

Partisan leanD+19.9

National environmentD+3.3

IncumbencyD+1.8

Incumbent's last over/under-performanceD+2.3

Fundraising gapD+1.9

Fundamentals estimateD+29.6

Input: partisan lean

D+26.7

Presidential vote relative to the nation, 2024 (and 2020).

Input: raised from itemized individual donors, through June 30

$1.0M D · $339K R

FEC filings; the model uses the log of the ratio.

Handicappers, for comparison

Cook: Safe D · Sabato: Safe D · Inside Elections: Safe D

Not an input to the projection.

Table view

All 8 polls in the average

“Share” is how much of today’s average each poll supplies. It depends on recency, the pollster’s record, whether the poll screens for likely voters, and how many other polls the same firm has in the race. It does not depend on sample size.

Dates	Pollster	Sample	Markey	Deaton	As published	Adjusted	Share of average
Aug 20–24	University of New Hampshire Survey Center for 7News	906 LV	49	30	D+19	D+19.1 moved 0.1 toward D	42%	source
Aug 5–12	YouGov for UMass Amherst \| WCVB-TV	800 RV	51	30	D+21	D+20.5 moved 0.5 toward R	26%	source
Jun 18–23	University of New Hampshire Survey Center	618 LV	50	34	D+16	D+16.1 moved 0.1 toward D	9.8%	source
Jun 8–12	Suffolk University for Boston Globe	500 RV	55	29.8	D+25	D+25.3 moved 0.1 toward D	14%	source
Apr 16–20	University of New Hampshire Survey Center	603 LV	55	32	D+23	D+23.1 moved 0.1 toward D	2.3%	source
Feb 12–16	University of New Hampshire Survey Center	616 LV	56	27	D+29	D+29.1 moved 0.1 toward D	0.5%	source
Jan 22–25	CygnalREP.-ALIGNED for Deaton's campaign	800 LV	54	30	D+24	D+27.4 moved 3.4 toward D	4.9%	source
Nov 19–23 ’25	Suffolk University for Boston Globe	500 RV	54	31	D+23	D+23.1 moved 0.1 toward D	0.6%	source

LV: likely voters. RV: registered voters. A: all adults. “Adjusted” is the published margin after removing the sponsor shift and the pollster’s measured house effect; the small print says how far that moved the poll. Dem.-aligned and Rep.-aligned mark polls paid for by a party, a campaign, or an allied group, or taken by a firm whose published work is mostly for one side. They are shifted by the average lean of such polls, then counted at full weight.

History

Recent results for this office

Year	Democrat	Republican	Result
2024	Elizabeth Ann Warren	John Deaton	D+19.8
2020	Edward J. Markey	Kevin J. O'Connor	D+33.1
2018	Elizabeth Ann Warren	Geoff Diehl	D+24.2
2014	Edward J. Markey	Brian J. Herr	D+23.9