Texas Attorney General Ken Paxton has defeated four-term incumbent Senator John Cornyn in the Republican Senate primary runoff, setting up a November general election contest that could help determine control of the US Senate. The result, called by major US networks shortly after polls closed on Tuesday, delivered a significant blow to the Republican establishment and underscored President Donald Trump's continued influence over his party's base.
Cornyn, 74, had represented Texas in the US Senate since 2002 and entered the race as the clear favourite, backed by major donors and senior party figures. He had previously served in Republican Senate leadership, making him one of Washington's most prominent establishment conservatives. Yet he struggled to energise Trump's populist base. Paxton, 63, campaigned against Cornyn as too old, too cautious and too aligned with Washington insiders, while presenting himself as one of Trump's most steadfast allies. Though Cornyn was outspent by a roughly 9-to-1 margin, Paxton overcame that financial gap after Trump endorsed him last week, having reportedly accused Cornyn of being "very disloyal" over his handling of voting reform legislation. In the first round of balloting in March, Cornyn had narrowly led 42.5% to 40.8%, but neither candidate crossed the 50% threshold needed to avoid a runoff.
Paxton's victory comes despite years of legal and ethical controversies, including a 2023 impeachment by the Republican-led Texas House of Representatives on allegations of bribery and misconduct. He was subsequently acquitted by the Texas Senate and has dismissed the proceedings as politically motivated. The bruising primary contest set a record as the most expensive Senate primary campaign in US history. "Tonight, we just made history," Paxton told supporters, calling Trump's endorsement "the most powerful force in politics." Cornyn, in a concession speech, said he would back Paxton in the general election.
Paxton will now face Democratic state Representative James Talarico, 37, in November. Talarico — who released a campaign ad labelling Paxton "the most corrupt politician in America" within minutes of the result being called — has attracted moderate and independent voters with what observers describe as a blend of faith-based populism and bipartisan appeal. Recent polls have shown a surprisingly tight race. Texas has not elected a Democrat to the US Senate since 1988, and Trump carried the state by nearly 14 points in 2024, but internal Republican memos have previously warned that Paxton's controversies could give Democrats a rare opportunity to compete for the seat.
The outcome is part of a broader pattern in which Trump-endorsed challengers have ousted Republican incumbents this cycle, including Louisiana Senator Bill Cassidy and Kentucky Representative Thomas Massie. Analysts note, however, that Cornyn's defeat also reflects an appetite within the Republican base for populist conservatives and a wariness of long-serving Washington figures — suggesting Trump's endorsement, while powerful, in some cases follows rather than leads his base. Cornyn becomes the first Republican senator from Texas to lose his party's nomination for re-election, effectively ending a 23-year congressional career. With the Texas seat now in play, the November contest between Paxton and Talarico is expected to attract national attention and significant fundraising on both sides.