Democrat Graham Platner will try to unseat GOP Sen. Susan Collins in a critical Senate matchup

Democrat Graham Platner will challenge Republican incumbent Sen. Susan Collins in the 2026 midterm election, according to CBS News projections following Tuesday's primary. This high-stakes Maine Senate race is viewed by Democrats as a top opportunity to flip a GOP-held seat. The matchup is considered a must-win for the Democratic party as they attempt to claim control of the Senate in November, marking a critical contest in the upcoming electoral cycle for both parties.