Maine

Maine Senate 2026

Lean RPrimary

Incumbent: Susan Collins (R)

Incumbent Susan Collins faces a genuinely competitive re-election bid in Maine. The race is expected to be decided by a narrow margin.

Democratic Primary
Graham Platner
Oyster farmer and military veteran
49.5%
Janet Mills
Governor of Maine
29.8%
David Costello
Former government official, 2024 Senate nominee
1.8%
Republican Primary
Susan Collins
U.S. Senator from Maine (incumbent)
41.6%

Polling

Polling Average

Polling average as of May 20, 2026 · updated 6 days ago

Recent Polls(11)

n 827LV
Platner48%
Collins41%
Mills
Costello
n 378LV
Platner51%
Collins45%
Mills
Costello
n 514LV
Platner61%
Collins
Mills28%
Costello2%
2026-03-26
n 530LV
Platner55%
Collins
Mills28%
Costello1%
2026-03-10
n 600LV
Platner44%
Collins42%
Mills
Costello
n 450LV
Platner43%
Collins
Mills38%
Costello
n 367LV
Platner46%
Collins
Mills39%
Costello4%
n 478LV
Platner64%
Collins
Mills26%
Costello1%
n 318LV
Platner37%
Collins
Mills47%
Costello1%
n 783RV
Platner45%
Collins41%
Mills
Costello
n 506LV
Platner58%
Collins
Mills24%
Costello1%

Prediction Markets