The attorney general’s victory is a crushing blow to the Texas GOP’s old guard, which has faltered in recent years against the Paxton-led insurgent wing.
Attorney General Ken Paxton won the Republican primary runoff for U.S. Senate Tuesday, ending over three decades of Sen. John Cornyn’s electoral dominance in what amounts to a watershed moment for GOP politics in Texas.
The Associated Press called the race for Paxton shortly after 8 p.m., about an hour after most polls closed in Texas.
Paxton’s win, coming on the heels of an eleventh-hour endorsement from President Donald Trump, will reverberate nationally. The result is a triumph for Paxton and his wing of the GOP, which prioritizes politicians’ zeal for destroying the left over traditional values like statesmanship and dealmaking. And it’s a massive blow to the Republican old guard in Texas and the political establishment in Washington, who were firmly behind Cornyn amid concerns about Paxton’s electability in November.
The outcome sets up a general election matchup between Paxton and Austin state Rep. James Talarico. Democrats have made no secret of their preference for Paxton, who they believe can be beaten due to the baggage he carries from a line of political and personal scandals. Paxton has run and won three times statewide, but Talarico will be by far his best-funded and most prominent opponent, and the first he will face running atop the ticket.
Tonight, he defeated one of the most successful politicians in Texas GOP history and a key figure in the Republican establishment in Washington. Had Cornyn won the primary and gone on to serve a fifth term, he would have set a Texas senatorial record for longevity. Instead, he becomes the first senator in Texas history to lose to a member of his own party since Ralph Yarbrough in 1970.
Onstage at his victory party in Plano, Paxton took the stage to cheers from supporters and elected officials in his camp. He praised Trump for endorsing him against the advice of Republicans in Washington. And he soaked in the gravity of the moment.
“Tonight, we just sent a Texas-sized message to Washington,” Paxton said.
Cornyn is the second sitting U.S. senator to lose a primary this month, following Louisiana Sen. Bill Cassidy, who failed to qualify for a Republican runoff earlier this month. Prior to this year, only two senators had lost primaries in the past 15 years — Sens. Richard Lugar of Indiana and Luther Strange of Alabama. Their successful primary challengers both went on to lose the general election.
Many of the Republicans who have been chased out of Congress in the past few cycles were either moderates or members who had crossed Trump, especially those who voted to impeach or convict him in the wake of January 6, such as Cassidy. But Cornyn does not fall into that category. He has been a reliable conservative vote throughout his career. His two biggest strays from MAGA orthodoxy recently were supporting aid to Ukraine and voting in favor of a bipartisan gun safety bill in the wake of the 2022 Uvalde school shooting.
And as Trump’s endorsement post made clear, Cornyn irked the president when he cast doubts on Trump’s electability in 2023 — far from a unique position. As Trump put it, “He was not supportive of me when times were tough.”
Paxton, by contrast, was one of two elected officials to attend Trump’s presidential campaign launch announcement in 2022, a demonstration of the ironclad loyalty he has shown the president.
The result is also a massive defeat for the Republican establishment in Washington, including Majority Leader John Thune, which has spent tens of millions on Cornyn’s behalf. For months, Cornyn, Thune and allies have made the case, both to voters and to the White House, that a Paxton candidacy would endanger Republicans’ chances in both the Senate race and down-ballot contests, especially the U.S. House races in Texas that could decide the balance of the lower chamber.
BY Gabby Birenbaum
Photo: Texas Attorney General Ken Paxton shakes hands with cheering supporters at his election night watch party in Plano after winning the Republican candidacy for U.S. Senate on May 26, 2026. Shelby Tauber for The Texas Tribune



