Social worker Lee Castillo was leading businessman Kurt Weiland in the Democratic primary in Utah's 1st Congressional District, but the race was too close to call.
Castillo led by more than 10 percentage points in votes tabulated by The Associated Press Tuesday night.
If he holds on, Castillo would be an underdog against incumbent U.S. Rep. Rob Bishop in the November general election in a predominantly Republican district that runs across the northern part of the state. United Utah Party candidate Eric Eliason will also be on the ballot.
Castillo is a gay Hispanic single father who has depicted himself as a voice for marginalized communities.
Weiland touted his experience in the U.S. Army and running a training and consulting firm. He says he would focus on keeping a close relationship with his district.
The two men got into a heated confrontation over the placement of signs at the Davis County Democratic convention in April. Police were called but no charges were filed.