Trump Drops 11th-Hour Bombshell Endorsement of Ken Paxton Over Sen. John Cornyn in Texas GOP Senate Runoff, Citing Filibuster, SAVE Act and Cornyn's 'Late' 2024 Support

President Donald Trump on Monday delivered an 11th-hour endorsement of Texas Attorney General Ken Paxton over incumbent Senator John Cornyn in the most expensive Republican Senate primary runoff in Texas history, blowing apart a months-long lobbying campaign by Senate GOP leadership and tilting an already-acrimonious race a week before polls close on May 26.

'I know Ken well, and I have seen him tested at the highest and most difficult levels, where he has come out as a true WINNER!' Trump wrote in a Truth Social post hours after early voting opened across the state. The president cited Paxton's support for eliminating the Senate filibuster and his backing of the Safeguard American Voter Eligibility (SAVE) Act, which would require documentary proof of citizenship to register to vote, and accused Cornyn of being 'very late' to support Trump's 2024 presidential bid. Cornyn finished first in the March primary with 43 percent of the vote, narrowly ahead of Paxton at 41 percent, sending both men into a runoff after neither cleared 50 percent.

The endorsement upends what Republican leaders had quietly considered an even fight. A Slingshot Strategies poll conducted for Texas Public Opinion Research last month found that a Trump endorsement of Paxton would widen the attorney general's lead to roughly 55 percent to 35 percent, and Senate Majority Leader John Thune had personally lobbied Trump for months to stay neutral or back the incumbent. Cornyn, a four-term senator and former whip, has tried to position himself as the only Republican who can hold the seat in November against Democratic nominee James Talarico, an Austin state representative who has out-fundraised both Republicans and leads them by between four and seven points in recent polling.

Paxton, who survived a 2023 impeachment trial in the Texas Senate over allegations of bribery and abuse of office, has built his campaign around a hard-edged MAGA platform, an aggressive run of federal lawsuits against the Biden administration during his decade as attorney general and a personal feud with Cornyn that predates the race. He told supporters at a Houston rally Monday night that Trump's endorsement 'closes the deal' and pledged to be the 51st vote to end the legislative filibuster and pass the SAVE Act in his first month in office. Cornyn, campaigning in Lubbock, told reporters he was 'disappointed but undeterred' and pointed to his Senate record on the bipartisan gun safety law, border funding and judicial confirmations as evidence that he is best suited to defend the seat.

Trump's move continues a remarkable purge of incumbents who have crossed him in his second term. Just 24 hours earlier, Trump-backed challenger Ed Gallrein toppled Representative Thomas Massie in Kentucky's 4th District after the president poured rally appearances and Truth Social posts into the race. Louisiana Senator Bill Cassidy fell to a Trump-backed primary opponent in March. Paxton would be the third sitting Republican lawmaker ousted at Trump's direction this cycle, and the runoff result is being closely watched as a measure of whether the president's grip on his party's primary electorate remains as absolute as it appeared in 2024. Early voting in Texas runs through Friday, with election day Tuesday, May 26.