With just one week remaining until Texas’ critical Republican Senate primary runoff, former President Donald Trump has thrown his full weight behind state Attorney General Ken Paxton, launching a direct challenge to three-term incumbent Senator John Cornyn, a longstanding fixture of the Republican Party establishment.
The endorsement marks the latest chapter in Trump’s ongoing effort to purge the GOP of lawmakers who do not align unwaveringly with his political movement. While Paxton has been one of Trump’s most loyal allies throughout his political career, he also carries a decades-long trail of ethical controversies and legal battles that have made him a deeply polarizing figure even within his own party.
As the state’s top law enforcement officer, Paxton famously threw his weight behind Trump’s failed 2020 bid to overturn the presidential election results. More recently, he traveled to New York City to rally in support of Trump during the former president’s 2024 hush-money criminal trial, which ended in a conviction on all counts. Like Trump, Paxton has built a political brand as a scandal survivor: he faces a lingering reputation for ethical misconduct, having settled a high-profile federal corruption indictment in 2024 without admitting any wrongdoing, survived a 2023 impeachment by the Republican-controlled Texas House of Representatives over allegations of fraud and obstruction of justice, and was recently caught up in a public divorce after his wife filed for separation amid revelations of multiple extramarital affairs.
“I know Ken well, have seen him tested at the highest and most difficult levels, and he is a winner!” Trump shared in a post on his Truth Social platform. “John Cornyn is a good man, and I worked well with him, but he was not supportive of me when times were tough.” His endorsement hinges on resentment over Cornyn’s delayed endorsement of Trump’s 2024 presidential bid: the incumbent waited until January 2024, more than a year after Trump entered the race, to publicly back his candidacy.
Cornyn, who has served in Senate Republican leadership from 2012 to 2024 and boasts a voting record that aligns with Trump’s agenda more than 99% of the time, pushed back against the attack in a post on X. “It is now time for Texas Republican voters to decide if they want a strong nominee to help our GOP candidates down ballot and defeat Talarico in November, or a weak nominee who jeopardizes everything we care about,” he wrote.
During the campaign, Paxton has attacked Cornyn for his past votes in favor of expanded gun safety regulations and accused him of failing to take aggressive enough action to enforce immigration controls along the U.S.-Mexico border. Cornyn’s campaign has in turn centered its messaging on Paxton’s long list of legal and personal scandals, framing him as too toxic to win the general election in November.
This endorsement is not an isolated incident: it fits into a broader pattern of Trump backing primary challengers against incumbent Republican senators who have broken with him. Just days before, Louisiana Senator Bill Cassidy, who voted to convict Trump during his 2021 second impeachment trial, lost his renomination bid to a Trump-endorsed challenger. On the same day Trump announced his Paxton endorsement, voters in Kentucky were heading to the polls to choose between incumbent Congressman Thomas Massie – who irked Trump by opposing key parts of his legislative agenda – and a challenger personally recruited by the former president.
Cornyn’s candidacy has drawn broad support from sitting Senate Republicans, who have served alongside the Texan for decades and view him as a reliable ally. The endorsement of Paxton has sparked widespread dismay among the Senate GOP caucus, with multiple high-profile senators openly criticizing the choice. Maine Senator Susan Collins labeled Paxton “ethically challenged,” while Alaska Senator Lisa Murkowski said she was “supremely disappointed” by Trump’s decision.
For Democratic operatives across the country, the prospect of a Paxton nomination is widely viewed as a rare opportunity to flip a longtime Republican Senate seat in Texas. It has been 32 years since a Democratic candidate won a statewide election in the deep-red state, but former Congressman Beto O’Rourke came within just 215,000 votes of unseating Senator Ted Cruz in 2018, and polling ahead of the 2026 general election already points to a competitive race. Democrat James Talarico, a state legislator who secured his party’s nomination outright earlier this spring, is already positioned to face the runoff winner. While Trump carried Texas by 14 percentage points in 2024, public polling suggests the general election will be a tight contest regardless of which Republican advances.
Early voting is already underway across Texas, and polling has consistently shown the runoff race is a dead heat. In the initial March primary, Cornyn finished a fraction of a percentage point ahead of Paxton, but fell just short of the 50% threshold needed to avoid a runoff, despite outspending his challenger by more than $65 million. Political analysts now widely believe that Trump’s late endorsement could deliver a decisive blow to Cornyn’s chances of holding onto his seat, reshaping the balance of power in the U.S. Senate ahead of the 2026 general election.