Newhouse advanced out of Tuesday's primary in Washington's 4th Congressional District, beating Republican challenger Loren Culp, a candidate endorsed by Trump.
The four-term incumbent will face Democrat Doug White, who also advances, NBC News projects, in the district rated as solid Republican this fall. Under Washington state’s open, nonpartisan primary system, the top two candidates, regardless of party, advance to the November election.
Newhouse and nine other House Republicans voted to impeach Trump in January 2021, charging him with "incitement of insurrection" for his role in the violent riot by a mob of his supporters. It was the most bipartisan vote on a presidential impeachment in history, doubling the five Democrats who voted to impeach Bill Clinton in 1998.
Like other impeachment supporters, Newhouse had out-fundraised his Trump-backed opponent. He brought in about $1.6 million, while Culp had raised $310,000 through the middle of July.
Reps. Peter Meijer, R-Mich., and Jaime Herrera Beutler, R-Wash., two others who voted to impeach the former president, also faced primary challengers backed by Trump on Tuesday in contests that marked a test of Trump's influence in GOP elections. Meijer was defeated by John Gibbs, a former Trump administration official.
Rep. Liz Cheney of Wyoming, the highest-ranking Republican to support impeachment and vice chair of the House committee investigating the Jan. 6 riot, faces her primary on Aug. 16.