Republican voters in Congressional District 3 have backed a Tucson businessman as their nominee to challenge eight-term Democratic U.S. Rep. Raúl Grijalva.

In early results with thousands of ballots left to be counted, Nicolas “Nick” Pierson has a significant lead over his GOP rivals teacher Edna San Miguel and Army veteran Sergio Arellano.

Pierson has roughly 57 percent of the vote, while Arellano had nearly 24 percent and San Miguel had about 19 percent of the vote, according to early results released by the Arizona Secretary of State.