Republican Senator John Cornyn of Texas (left) and Texas Attorney General Ken Paxton.
eddie seal | Bloomberg | getty images
Polls are open in the Republican Senate primary runoffs in Texas as incumbent Senator John Cornyn tries to avoid a primary challenge from state Attorney General Ken Paxton, who has the endorsement of President Donald Trump.
The winner of the Republican runoff will face Democratic state Assemblyman James Tallarico in the general election in November. The race is expected to be one of the most expensive in the country as the GOP competes to retain control of the Senate and Democrats attempt to win a long-sought Senate seat in Texas.
Cornyn finished ahead of Paxton by a narrow margin in the March primary, but failed to garner enough votes to avoid a runoff.
Trump’s endorsement of Paxton last week shocked the Republican-controlled Senate, which has poured significant resources into Cornyn’s re-election bid. Cornyn also took broad steps to improve his relationship with Trump, which has been strained for years.
The Republican primary in Texas has been one of the most upsets of the 2026 campaign cycle. Cornyn’s campaign has criticized Paxton, a close Trump ally, over several ethics and legal scandals that have dogged him and his office during his tenure as the Lone Star State’s top law enforcement official.
Paxton was impeached by the Texas House of Representatives and acquitted by the Senate and convicted of securities fraud. he was recently divorced his wife which he described as having “biblical basis”.
State Representative James Tallarico, Democrat from Texas and candidate for U.S. Senate, speaks during the kickoff event of his Take Back Texas tour in Austin, Texas, U.S., on Tuesday, Feb. 17, 2026.
Joel Angel Juarez | Bloomberg | getty images
Paxton’s campaign, meanwhile, has long tried to portray Cornyn as a Washington establishment figure.
Cornyn has held an important position in the Senate for four times. He was the Senate Republican whip, number one. Second position in the upper house from 2013–2019. He lost a bid to lead Republicans in the Senate in 2024 to Senate Majority Leader John Thune, but is still popular among his colleagues. Senate Republicans believe Cornyn would be a more formidable and less expensive opponent for Tallarico in the general election.
Paxton is the favorite to come out on top in the primaries after Trump’s endorsement. A Quantus Insights The poll released Monday found Paxton leading Cornyn by 9.3 percentage points on Election Day.
Trump has made defeating his political enemies in the GOP a priority in his second term. Senator Bill Cassidy, R-La., failed to qualify for a runoff in Louisiana in early May after Trump endorsed his opponent in the primary. And Rep. Thomas Massie, R-Ky., a frequent Trump foil in his second term, lost the primary to Trump-backed challenger Ed Galren.
in support of paxton true socialTrump said Cornyn “is a good man, and I worked well with him, but he didn’t support me when times were tough.”
The president said, “Ken Paxton has been through a lot, in many cases, very unfairly, but he is a warrior and knows how to win.” “Our country needs fighters, and also loyalty to greatness.”