Senate battlegrounds in Georgia, Michigan, and Maine determine which party controls the chamber in 2027

Nine Senate seats are rated as battleground races heading into November 2026. Democrats defend seats in Georgia (Jon Ossoff) and Michigan — both states Trump won in 2024. Republicans defend a seat in Maine (Susan Collins), a state Kamala Harris won. Democrats must hold all their seats and flip four Republican-held seats to take the majority. As of March 2026, four Senate Democrats and six Senate Republicans announced they would not seek re-election, opening additional competitive contests in Alabama, North Carolina, and Iowa.