Adam Laxalt, a former Nevada attorney general, has won the state’s Republican primary for Senate and will face Senator Catherine Cortez Masto, a Democrat, in what is likely to be a highly competitive November general election.
Mr. Laxalt’s victory over Sam Brown, a retired Army captain, was declared by The Associated Press. He and Ms. Cortez Masto, who is seen as one of Democrats’ most vulnerable incumbents, will now prepare for a costly monthslong clash as Republicans try to take back control of the Senate.
A co-chair of the 2020 Trump campaign in Nevada, Mr. Laxalt was endorsed by both former President Donald J. Trump and Gov. Ron DeSantis of Florida, two of the most popular figures in the Republican Party.
Following Mr. Trump’s cue, Mr. Laxalt has promoted baseless claims of fraud in the 2020 election, and he began laying detailed groundwork to fight election fraud in his own race this year, months before any votes were cast.
The endorsements were a cornerstone of Mr. Laxalt’s campaign, with both national leaders visiting the state to rally for him and recording television commercials on his behalf. Mr. Laxalt also received a boost from the Club for Growth, an influential conservative anti-tax group, whose political action committee spent nearly $1 million.
The Republican primary race had intensified in recent months between Mr. Laxalt and Mr. Brown, who drew significant support from some local Republican groups as he criticized his rival’s Washington connections and portrayed himself as the “outsider” who could bring change to the Capitol.
Now a small-businessman, Mr. Brown earned a Purple Heart after being seriously injured in Afghanistan and still bears the scars on his face.
Mr. Laxalt, a grandson of Paul Laxalt, a former senator from the state, and son of Pete Domenici, a former senator from New Mexico, has also embraced the set of conspiratorial beliefs known as replacement theory, telling supporters in campaign appearances that “the left” wants to transform the country by allowing immigrants to enter the country illegally.
Mr. Laxalt has simultaneously courted Latino voters, who are expected to be pivotal in the November election.
Ms. Cortez Masto has already spent roughly $13.5 million on the race, according to AdImpact, which tracks ad spending. She has blanketed the airwaves with television ads in English and Spanish to highlight her work to deliver pandemic aid to the state.
The race has also attracted heavy outside spending. Somos PAC, which focuses on Latino voters, has spent $2.8 million to defend Ms. Cortez Masto, the first Latina elected to the Senate, and to portray Mr. Laxalt as “not for us” in advertisements in English and Spanish.