PLANO, Texas (AP) — Texas Republicans are deciding their U.S. Senate nominee in Tuesday’s runoff election, concluding a prolonged, contentious and costly primary campaign where President Donald Trump made a late intervention to influence the outcome in his ongoing effort to remove GOP officials he considers insufficiently loyal.
Trump’s backing of state Attorney General Ken Paxton against four-term Sen. John Cornyn provides the challenger with crucial momentum and threatens to make Cornyn the first Republican senator in Texas to lose a primary battle for renomination.
This comes even though Cornyn’s campaign and supporting organizations have invested approximately $90 million in television advertisements since last year, with most of those funds used to attack Paxton.
The race represents another GOP primary where Trump has attempted to retaliate against a Republican he views as not sufficiently faithful. This month, he has successfully supported challengers against sitting officials in Louisiana, Kentucky and Indiana, demonstrating his continued sway over primary election voters.
Paxton’s campaign team and a supportive super PAC launched advertisements highlighting the endorsement within one day of Trump’s announcement. Cornyn recognized that Trump’s intervention would affect the race but indicated he would continue fighting.
“I know who gets to choose our senators, and it’s the people of Texas,” he said hours after the endorsement.
The victor will face Democratic state Rep. James Talarico in November’s general election.
Tuesday’s runoff elections will also determine Democratic U.S. House candidates for districts in Dallas and Houston that strongly favor Democrats, plus a San Antonio-area seat the party aims to capture.
Cornyn outpaced Paxton in the March primary but couldn’t secure a majority in the three-candidate race that also featured U.S. Rep. Wesley Hunt, who placed a distant third.
This occurred following a sustained advertising effort by Cornyn’s campaign and allied organizations, primarily targeting Paxton over ethical and personal controversies. The two-term attorney general was cleared in a 2023 impeachment proceeding when accusations of extramarital relationships emerged. Last year, Paxton’s wife initiated divorce proceedings, citing “biblical grounds.”
The coalition of pro-Cornyn organizations has maintained its offensive strategy, outspending Paxton’s campaign and two allied super PACs $16.5 million to $5.9 million since March 3, according to ad-tracking firm AdImpact.
Trump had promised to make an endorsement right after the primary, requesting the unselected candidate to step aside. However, he delayed action until after early voting commenced on May 18.
“Ken Paxton has gone through a lot, in many cases, very unfairly, but he is a Fighter, and knows how to win,” Trump wrote in a social media post endorsing him. “Our Country needs Fighters, and also Loyalty to the Cause of Greatness.”
Pro-Cornyn organizations recently have broadcast advertisements criticizing the attorney general office’s management of a Waco sex abuse case. Pro-Paxton organizations have highlighted Cornyn’s strained relationship with Trump.
The hostile atmosphere could reduce participation in an election already challenged by occurring one day after Memorial Day, Texas Republican strategist Tyler Norris said. Approximately 2 million of Texas’ 18.7 million voters took part in the GOP primary.
The situation could benefit Paxton, whose supporters come more from the most dedicated Trump base in Texas, said Norris, who isn’t connected with either campaign.
“The defining battle lines are based around hyper-negative messaging, which dampens turnout to begin with,” he said. “So who is going to show up is the hardest of the hard core.”
Trump in his endorsement also criticized Cornyn, as he has done with other Republicans who don’t align completely with the president.
He attacked Republican Louisiana Sen. Bill Cassidy as “a Disloyal Disaster” on May 16, before Cassidy lost a GOP primary for the position he has occupied since 2015. The two-term senator had voted to find Trump guilty after his 2021 impeachment trial regarding the Jan. 6, 2021, attack on the U.S. Capitol. Trump supported U.S. Rep. Julia Letlow, who moved forward to a runoff with John Fleming, the state treasurer. Cassidy placed far behind them.
Last week, Trump expressed satisfaction as Kentucky Rep. Thomas Massie, a critic of the Trump administration’s approach to the Jeffrey Epstein files, lost his primary to Ed Gallrein. Trump labeled Massie “the worst congressman in the history of our country.”
In supporting Paxton, Trump said Cornyn “was not supportive of me when times were tough” and that “John was very late in backing me.”
Cornyn indicated in 2023 that Trump couldn’t secure the presidency again in 2024 and that his “time has passed him by.” He also initially opposed Trump’s proposal for a border wall between the U.S. and Mexico — a project he now endorses.
Senate GOP leadership supported Cornyn, arguing he would perform better in the general election. Some GOP strategists have contended a Paxton nomination would require millions of additional dollars to promote in the fall, when resources could be used defending Republican seats in more competitive states. Democrats need to gain a net of four seats to control the majority.
Newly elected Rep. Christian Menefee and veteran Rep. Al Green are competing for the party nomination in Texas’ 18th District, which the Republican-controlled Texas Legislature redesigned last year to assist the GOP. The new boundaries created a race between incumbents and concludes a complex series of elections in the Houston region. Menefee was elected in a special runoff in January to the seat previously held by the late Rep. Sylvester Turner, who died in March 2025.
Menefee finished slightly ahead of Green in the March 3 primary but didn’t achieve a majority to prevent the runoff.
Former Rep. Colin Allred and U.S. Rep. Julie Johnson are contending in the Dallas-area 33rd District. Johnson was elected to the position in 2024, the year Allred lost his U.S. Senate challenge to Republican Sen. Ted Cruz. Allred was seeking Senate office again this cycle but abandoned his campaign and instead is attempting to return to the House.
Near San Antonio, Democratic leadership is working to stop Maureen Galindo, who has made antisemitic statements, from winning the party’s runoff against Johnny Garcia. While Texas lawmakers redrew the 35th District to favor Republicans, Democrats consider it attainable and don’t want Galindo’s previous remarks to hinder them.
