United States / Maine / Senate Election
2026 Maine Senate Democratic primary
Maine polling average: Platner (D) 69.3% — Mills (D) 15.1% — Platner (D) +54.2Also: Costello (D) 4.7%Pollytic average to 8 Jun 2026: recent, larger polls weigh more; no institute counts more than once.
Election date
Held on
Results
78% reporting ·
| Candidate | Votes | Share | |
|---|---|---|---|
| Graham PlatnerProjected winnerDemocratic Party | 148,918 | 72.0% | |
| Janet MillsDemocratic Party | 39,929 | 19.3% | |
| David CostelloDemocratic Party | 17,171 | 8.3% | |
| Andrea LaFlammeDemocratic Party | 842 | 0.4% |
| County | Leader | Lead | Votes |
|---|---|---|---|
| Kennebec | Platner | +50.2 | 14,322 |
| Androscoggin | Platner | +49.6 | 11,291 |
| Sagadahoc | Platner | +58.0 | 7,478 |
| Aroostook | Platner | +43.4 | 4,506 |
| Somerset | Platner | +48.2 | 2,733 |
| Piscataquis | Platner | +45.5 | 1,412 |
How the count progressed
Updated
Polls vs result
The last polling average before the vote () against the actual result.
- Mean absolute error
- 3.5 pts
- Error on the winner’s margin
- +2.3 pts
| Candidate | Average | Result | Error |
|---|---|---|---|
| Platner (D) | 69.7% | 72.0% | −2.3 |
| Mills (D) | 14.7% | 19.3% | −4.6 |
| Costello (D) | 4.6% | 8.3% | −3.7 |
| Democratic | — | 0.4% | — |
Error = average − result, in percentage points. A dash means the party or candidate was missing from the average or the result; it is left out of both errors.
Polling trend
The average of recent polls. Newer polls and more accurate pollsters count more. How it’s calculated
Latest polls
Each poll as published, with its pollster, fieldwork dates, sample size and a link to the source.
How to read a poll
- Sample size is how many people were asked. More people means less random error, never none.
- ±3 is the margin of error: the real figure is likely within 3 points either way of the one shown.
- Two polls can differ because they were taken on different dates, with different methods and different samples.
- est. means the institute did not publish a margin of error, so it is estimated from the sample size.
- The average smooths this out: it combines recent polls, so one unusual poll cannot swing the picture.
What the polls say
Platner (D) leads the polling average in Maine on 69.3%, 54.2 points ahead of Mills (D) (15.1%). The biggest shift over the past month is Mills (D), down 13.5 points.
2 polls from 2 institutes were published in the last 30 days of polling. The most recent is from Tavern Research (D), published 8 Jun 2026. The average gives recent and larger polls more weight and counts no institute more than once; read how it works.
Candidates
Who is standing, in order of the polling average, then the result.
- Graham PlatnerDemocratic
- Janet MillsDemocratic
- David CostelloDemocratic
Government
Who governs Maine now.
Janet Mills
Governor of Maine