Texas GOP Senate primary upset: Ken Paxton defeats John Cornyn in runoff

Trump‑backed Ken Paxton ousted longtime incumbent Sen. John Cornyn in the Texas Republican Senate primary runoff on May 26, 2026, with a decisive 64% margin; Cornyn conceded. Downballot races (AG, Lt. Gov.) also decided. The result reinforces Trump's grip on the GOP and raises the general‑election competitiveness, with Democrat James Talarico now seen as a potential crossover candidate. Parallels to Roy Moore and Herschel Walker highlight risks for the GOP. A voting glitch in Fort Bend County fuels election‑integrity debates. High debate value: establishment vs. Trump wing, implications for Senate control and 2026 messaging.