Democrat Jared Golden, a U.S. Marine veteran, has defeated two-term Republican Representative Bruce Poliquin in Maine’s Second District, AP projects, as the state’s first use of ranked-choice balloting in a congressional race proved consequential.

Poliquin, the incumbent, led after ballots were initially tabulated, though no candidate had an absolute majority. However, under ranked-choice voting, the lowest-choice candidates were eliminated and their votes reallocated to their second choices. Under that system, Golden, the Democrat, pulled ahead.

Poliquin sued to stop the runoff, however a judge denied his request for a temporary restraining order, allowing the process to continue, the New York Times reported.