Sen. Gary Peters of Michigan, who led Senate Democrats’ campaign efforts for two election cycles, announced he will not seek a third term in 2026, opening a key battleground seat both parties will likely fight for.

Peters, 66, said he always intended to pass the reins to the next generation. “I never saw Congress as a lifetime career. After three terms in the House and two in the Senate, it’s time for me to move on,” he said in a YouTube video.

His decision complicates Democrats’ efforts to regain control of the Senate, where Republicans now hold a 53-47 majority. It also forces them to defend an open Michigan seat without an incumbent in a state that Donald Trump won in 2024.

Former U.S. Transportation Secretary Pete Buttigieg, who recently moved to Michigan, is a likely contender for the Senate race. Meanwhile, Democrats are also gearing up for the 2026 gubernatorial election as Gov. Gretchen Whitmer nears the end of her term.

Detroit Mayor Mike Duggan plans to run for governor as an independent, while Republican state Senate leader Aric Nesbitt and Democratic Secretary of State Jocelyn Benson have launched their campaigns.

Peters, a moderate who chaired the Senate Homeland Security Committee from 2021 to 2025, was praised for helping Democrats retain the Senate in 2022. However, the party lost its majority in 2024. His departure leaves Michigan Democrats facing a tough challenge in both the Senate and gubernatorial races.