Rep. Harriet Hageman of Wyoming won the state's Republican Senate primary on August 18, 2026, defeating her challenger and advancing to the general election in a state that routinely delivers some of the largest Republican margins in the nation. Hageman, who has held Wyoming's at-large House seat since 2023, received the endorsement of former President Donald Trump in her Senate bid.

Hageman first rose to national prominence in 2022 when she defeated then-Rep. Liz Cheney in the Republican primary, a race widely seen as a referendum on Cheney's vote to impeach Trump following the January 6, 2021 Capitol riot. Her win over Cheney was one of the most high-profile primary defeats of that election cycle. Hageman has since maintained strong alignment with Trump's political priorities in the House.

Wyoming is among the most Republican-leaning states in the country, making the general election outcome heavily favorable for the GOP nominee. Hageman's Senate primary victory effectively positions her as the expected successor to the seat as she seeks to move from the House to the upper chamber of Congress.

The primary result continues a pattern of Trump-endorsed candidates performing strongly in intraparty contests, particularly in deeply conservative states. Hageman has been a consistent supporter of Trump's agenda during her time in the House, and her Senate campaign built on that alignment as its central appeal to Wyoming Republican voters.