Michigan Sen. Gary Peters, who led the Democrats’ Senate campaign efforts the past two election cycles, has announced he will not seek a third term in 2026, creating a highly contested battleground seat expected to be coveted by both major political parties.

Democratic Sen. Gary Peters won’t run for re-election in Michigan in 2026, creating a pivotal open Senate seat in one of the most tightly divided battleground states in the U.S.

His unexpected retirement in the battleground states comes in an already difficult Senate cycle for Democrats.