SPOKANE, Wash. -

Republicans Clint Didier and Dan Newhouse have advanced from a crowded field of candidates in the open 4th Congressional District primary.

Didier, a former NFL star, and Newhouse, a Yakima Valley farmer, drew the most votes in early returns Tuesday evening. It's the first time in state history that two candidates of the same party advanced to the general election in a U.S. House race.

Washington has a top-two primary system, meaning that the top two vote-getters regardless of party affiliation advance to the general election.

A dozen people -- eight Republicans, two independents and two Democrats -- were seeking to replace retiring Republican Rep. Doc Hastings.

The 4th District in central Washington, which includes Yakima and the Tri-Cities, hasn't elected a Democrat since 1992.