President Donald Trump endorsed former Texas Attorney General Ken Paxton in the Republican Senate primary runoff, bypassing incumbent Sen. John Cornyn in a high-profile display of the president's ongoing sway over GOP primary politics. Trump praised Paxton as an "America First patriot" in announcing his support, setting up a direct clash between the former attorney general and one of the Senate's most senior Republicans.

The endorsement is widely seen as a snub of Cornyn, a longtime Senate fixture who has served in leadership and maintained a generally aligned relationship with Trump during his first term. Despite that record, Trump opted to back Paxton, whose tenure as attorney general was marked by both aggressive legal battles against the Biden administration and a high-profile impeachment by the Texas House in 2023, from which he was ultimately acquitted by the state Senate.

The Texas runoff is among the most closely watched Republican primary contests of the 2026 cycle. Paxton's supporters argue that his willingness to challenge federal authority and his acquittal make him a strong conservative standard-bearer. Cornyn's allies contend that his Senate seniority and institutional relationships make him a more effective legislator for Texans.

Trump's endorsement adds to a pattern of primary interventions this cycle, with the president also weighing in on other contested Republican races across the country. The Texas Senate seat carries considerable weight given the state's size, its electoral college importance, and the balance of power in the Senate. The runoff is expected to draw national attention and significant fundraising on both sides.