Texas Attorney General Ken Paxton defeated four-term U.S. Sen. John Cornyn in Tuesday’s Republican primary runoff for U.S. Senate, ending Cornyn’s bid for a fifth term and giving President Donald Trump a major victory in one of the country’s most expensive Senate primary fights.
The Associated Press projected Paxton as the winner Tuesday night. Paxton will now face Democratic nominee James Talarico in the November general election.
As previously reported by The Dallas Express, Cornyn and Paxton advanced to the runoff after the March 3 primary, when neither candidate crossed the 50% threshold needed to win the Republican nomination outright.
Cornyn Outspent Paxton
Paxton’s victory came despite a major spending gap.
Cornyn and allied groups spent about $90 million on advertising, while Paxton’s campaign and PAC spent only a fraction of that, AP reported.
Bloomberg Government reported that Republican candidates and allied groups spent almost $130 million in ads across the Texas Senate primary contest.
The race had already broken records before the March primary. AdImpact reported in February that the 2026 Texas Senate race had surpassed $122 million in ad spending, making it the most expensive Senate primary on record at that point.
Trump Endorsed Paxton Late In Race
Trump endorsed Paxton after early voting began, giving the attorney general a major boost in the final stretch of the runoff.
As previously reported by The Dallas Express, Trump gave Paxton his “Complete and Total Endorsement” on Truth Social, writing, “KEN PAXTON WILL NEVER LET YOU DOWN!”
Prediction markets also moved sharply toward Paxton after Trump’s endorsement. As previously reported by The Dallas Express, Kalshi and Polymarket listed Paxton at 96% to win the runoff on Monday, one day before voters finished casting ballots.
Paxton had campaigned as the more aggressive pro-Trump candidate, while Cornyn entered the race with institutional support from Senate Republican leadership and much of the Texas Republican establishment.
General Election Set
Talarico, an Austin-area state representative, won the Democratic primary earlier this year after defeating U.S. Rep. Jasmine Crockett (D-Texas) and Ahmad Hassan, according to Ballotpedia.
The November matchup is expected to draw national attention. Democrats are expected to target Paxton’s legal and political history, while Republicans are expected to frame the race around immigration, border security, the economy, and support for Trump’s agenda.
Texas has not elected a Democrat to statewide office since 1994.
Paxton’s victory ends Cornyn’s more than two decades in the Senate and gives Texas one of the highest-profile general election races of the 2026 cycle.
