Wisconsin Democrats scored a major upset victory Tuesday night, winning a state Senate seat in a district that went for Donald Trump by double digits in 2016.

Caleb Frostman defeated state Rep. Andre Jacque (R) for the open seat in District 1 that was previously held by state Sen. Frank Lasee (R), who resigned to take a job in Gov. Scott Walker’s administration. Frostman will be on the ballot again in November for the regular election.

Republicans held on to a state Assembly seat in District 42 that also held a special election Tuesday.

Although Frostman’s term is short, his win is a huge victory for the Democratic Party. Not only was the seat held by a Republican, but Trump defeated Democratic rival Hillary Clinton there by 17 points in the 2016 presidential election. Trump also won the state of Wisconsin overall.