Texas Republican Sen. John Cornyn (left) and Texas Attorney General Ken Paxton.
Eddie Seal | Bloomberg | Getty Images
The Republican Senate primary runoff elections have begun in Texas, with incumbent Sen. John Cornyn trying to fend off a primary challenge from Attorney General Ken Paxton, who is backed by President Donald Trump.
The winner of the Republican runoff will face Democratic state Rep. James Talarico in the November general election. The race is expected to be one of the most expensive in the nation, as Republicans aim to maintain their Senate majority and Democrats seek to win a long-coveted Senate seat in Texas.
Mr. Cornyn narrowly defeated Mr. Paxton in the March primary, but was unable to gather enough votes to avoid a runoff.
Mr. Trump’s endorsement of Mr. Paxton last week shocked the Republican-controlled Senate, which had poured significant resources into Mr. Cornyn’s re-election. Mr. Cornyn also took extensive steps to repair his long-strained relationship with Mr. Trump.
The Texas Republican primary was one of the most confusing of the 2026 election cycle. Mr. Cornyn’s campaign has slammed Mr. Paxton, an ally of President Trump, over a number of ethical and legal scandals that have plagued him and his office during his tenure as the Lone Star State’s top law enforcement official.
Mr. Paxton was impeached by the Texas House of Representatives, acquitted by the Senate, and faces charges of securities fraud. He recently divorced his wife on “biblical grounds.”
State Representative James Talarico, a Texas Democrat and U.S. Senate candidate, speaks at the kickoff event for his “Take Back Texas” tour in Austin, Texas, U.S., Tuesday, February 17, 2026.
Joel Angel Juarez | Bloomberg | Getty Images
Meanwhile, Paxton’s campaign has been trying to mold Cornyn into a longtime Washington establishment figure.
Mr. Cornyn is an incumbent who has held important positions in the Senate for four terms. He was the Senate Republican whip, number one. He served as number 2 in the Senate from 2013 to 2019. Although he ran for Senate Republican leader in 2024 and lost to Senate Majority Leader John Thune, he remains popular with his colleagues. Senate Republicans believe Mr. Cornyn will be a tougher and lower-cost challenger to Mr. Talarico in the general election.
Mr. Paxton is the front-runner with the support of Mr. Trump and is likely to rise to the top in the primary. A Quantus Insights poll released Monday found Mr. Paxton leading Mr. Cornyn by 9.3 points ahead of Election Day.
President Trump has made defeating his political opponents within the Republican Party a priority for his second term. Sen. Bill Cassidy (R-Louisiana) failed to qualify for the runoff election in Louisiana in early May after President Trump endorsed his opponent in the primary. Additionally, Rep. Thomas Massie (R-Kentucky), a frequent Trump foil during his second term, lost in the primary to Trump-backed challenger Ed Gullane.
President Trump endorsed Paxton on Truth Social, saying Cornyn was “a good person and I worked well with him, but he didn’t support me in tough times.”
“Ken Paxton has faced great injustice on many occasions, but he is a fighter and he knows how to win,” the president said. “Our country needs fighters, and we also need loyalty to a great cause.”
