Natasha Alcala is running against Susan Collins (R, incumbent).
Collins is the only Republican senator in a state Kamala Harris won in 2024. Cook Political Report and Sabato's Crystal Ball both rate this race a Toss-up. Collins faces record low approval - only 14% favorable with 57% unfavorable. If Democrats flip this seat, it would be a major pickup.
Crowded Democratic primary led by Graham Platner (oyster farmer/veteran) at 58% and Gov. Janet Mills at 24% in Oct 2025 polling; Alcala polls below 2%. Jordan Wood has raised $1.6M, David Costello also in the field. Alcala has $0 in FEC-reported contributions. Maine uses ranked-choice voting for both primary and general. 94% of voters say they don't know enough about her. Alcala previously filed to run against Sen. Angus King in 2024 but withdrew before the primary. She ran unsuccessfully to become a Maine Democratic Party delegate to the 2024 national convention.
Key dates to watch: Primary on June 9, 2026 and General Election on November 3, 2026.