Senate · 2026

Maine Senate

Troy Jackson (D)v.Susan Collins (R)LEAN D

Incumbent: Susan Collins, currently Republican. Fundraising term uses Graham Platner's receipts: he was the Democratic nominee at the June 30 reporting date; Troy Jackson was named July 25.

Projected margin

D+3.0

Nine in ten outcomes: D+12 to R+6

Chance of winning

72%

Troy Jackson

Polls alone

D+2.3

11 polls from 11 pollsters; latest Sep 15. Weight in projection: 70%.

Fundamentals alone

D+4.7

Weight in projection: 31%.

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+6.3

National environmentD+3.3

IncumbencyR+1.8

Incumbent's last over/under-performanceR+3.4

Fundraising gap0.0

Fundamentals estimateD+4.7

Input: partisan lean

D+8.4

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

Input: raised from itemized individual donors, through June 30

$6.2M D · $6.3M R

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

Handicappers, for comparison

Cook: Tossup · Sabato: Tossup · Inside Elections: Tilt R

Not an input to the projection.

Table view

All 11 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	Jackson	Collins	As published	Adjusted	Share of average
Sep 14–15	Quantus Insights	621 LV	47.4	47.6	Even	D+0.1 moved 0.3 toward D	14%	source
Sep 8–10	Rasmussen Reports	1,033 LV	46	45	D+1	D+0.9 moved 0.1 toward R	13%	source
Sep 2–8	YouGov	1,335 LV	48	44	D+4	D+3.5 moved 0.5 toward R	13%	source
Aug 31 – Sep 6	CNN	880 LV	48	45	D+3	D+2.9 moved 0.1 toward R	12%	source
Aug 26–28	Abacus Data	327 LV	50	42	D+8	D+7.8 moved 0.2 toward R	11%	source
Aug 6–10	Beacon Research/Shaw & Co. Research for Fox News	1,000 RV	48	46	D+2	D+2.1 moved 0.1 toward D	6.3%	source
Jul 27 – Aug 1	Garin-Hart-Yang Research GroupDEM.-ALIGNED for Senate Majority PAC	802 LV	49	45	D+4	D+0.7 moved 3.3 toward R	9.9%	source
Jul 15–20	University of New Hampshire Survey Center	1,178 LV	49	46	D+3	D+3.1 moved 0.1 toward D	5.8%	source
Jul 7–8	Z to A ResearchDEM.-ALIGNED for a pro-Shah group	988 LV	47	48	R+1	R+4.4 moved 3.4 toward R	5.9%	source
Jul 7	Public Policy PollingDEM.-ALIGNED for Platner's campaign	785 RV	49	44	D+5	D+1.5 moved 3.5 toward R	4.2%	source
Jul 4–6	Wedgewood Polls	405 LV	48	43	D+5	D+5.4 moved 0.4 toward D	5.8%	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	David Allen Costello	Demi Kouzounas	R+23.8
2020	Sara I. Gideon	Susan M. Collins	R+8.6
2018	Zak Ringelstein	Eric L. Brakey	R+24.8
2014	Shenna Bellows	Susan M. Collins	R+37.0