Senator John Cornyn (R-TX) lost the Texas Senate GOP primary on May 27, 2026, by a margin of 27 points, receiving 36.2% of the vote compared to Texas Attorney General Ken Paxton's 63.8%, according to the Associated Press. Polls leading up to the election had indicated Cornyn would lose but did not accurately predict the extent of his defeat. An average of three polls suggested a loss by approximately 8 points, while only one of six polls from May indicated a double-digit loss for Cornyn.
Factors contributing to Paxton's unexpected performance include a last-minute endorsement from former President Donald Trump and lower voter turnout for Cornyn. Paxton stated, "President Trump is the leader of our party, and his endorsement is the most powerful force in politics." In the runoff, Cornyn received 501,725 votes, a significant decrease from the 910,382 votes he garnered in the March primary, where Paxton received 878,564 votes. In total, 1,387,674 ballots were counted in the runoff.
Paxton will compete against Texas state Representative James Talarico in the general election, which is expected to be highly competitive as Talarico aims to be the first Democrat to win statewide in Texas in 30 years. Following Paxton's victory, Talarico raised $600,000 in the first two hours of fundraising, marking a strong start for his campaign.