IOWA — A special election in western Iowa on Tuesday puts Iowa Senate Republicans’ supermajority at risk.

Democrat Catelin Drey is running against Republican Christopher Prosch in Iowa’s Senate District 1, which includes much of Sioux City in Woodbury County. Drey and Prosch are vying to fill the seat of the late Rocky De Witt, who died in June. He was elected to the Iowa Senate in 2022.

Republicans currently control 33 seats in the Senate. A win by Prosch would allow the party to maintain its supermajority.