Trump-backed Paxton defeats Cornyn in historic Texas Senate runoff

Ken Paxton’s 28-point rout of John Cornyn was more than a primary upset. It was a blunt measure of what loyalty to the old Republican establishment is worth inside a Texas GOP now dominated by Donald Trump’s approval.

Paxton took about 64% of the vote to Cornyn’s 36% in the Republican runoff held Tuesday, May 26, 2026. Trump’s endorsement came only a week earlier, on May 19, and it proved decisive in a race that had become a referendum on whether a four-term senator could survive in a party where institutional credibility now carries less weight than allegiance to Trump and the MAGA base.

The defeat was historic. The Associated Press said Cornyn became the first Republican senator from Texas to lose renomination, an extraordinary fall for a longtime figure who once sat near the center of Senate Republican power and was a former contender for leadership. His loss also capped one of the most expensive Senate primaries in U.S. history, with Republicans spending more than $100 million in a battle that split the party and exposed the shrinking space for traditional conservatives in Texas.

Cornyn spent more than a year trying to blunt Trump’s hostility by aligning himself with the former president’s agenda and making public gestures of loyalty. That effort was not enough. The final days of the race were defined by Trump’s late intervention on Paxton’s behalf, which helped turn an already bitter contest into a test of who could claim the MAGA mantle more credibly in a state long seen as a Republican stronghold.

Paxton’s victory also reflects the durability of his own political brand. Despite years of controversy and impeachment-related battles, the Texas attorney general proved stronger in a Republican runoff than the better-known senator who once embodied the party’s governing wing. Texas GOP leaders quickly congratulated him, even as Democrats pointed to the result as evidence that Trump can still decide Republican nominations and punish incumbents he views as insufficiently loyal.

The runoff now sets up a November general election against Democrat James Talarico. That matchup gives Republicans a new risk point in a state they have long expected to hold, especially with Paxton carrying a record that multiple observers say could make the seat more vulnerable than Cornyn would have been. In Texas, the race ended with more than a nomination settled. It showed how far the party has moved from the old guard that once treated Cornyn’s brand of conservatism as the default.