Texas Attorney General Ken Paxton (R-TX) won the Republican runoff for the U.S. Senate on May 26, 2026 [1], defeating incumbent Senator John Cornyn [2].
The victory represents a significant shift in the Texas GOP, as a Trump-endorsed challenger successfully ousted a sitting incumbent in a high-profile primary battle.
Following the results, Paxton said he was grateful to President Donald Trump for his support during the campaign. He said the win was due to the influence of the former president's backing in the primary process.
"I want to thank President Donald Trump for his unwavering support," Paxton said. "His endorsement was the most powerful force in politics" [3].
Paxton's campaign focused on the alignment between his legal priorities and the MAGA movement. The attorney general said he was grateful to President Trump for the support that helped him secure the nomination [4].
Throughout the runoff, the contest was framed as a test of the incumbent's standing within the current Republican base. The defeat of Cornyn marks a rare instance of an incumbent senator losing a primary runoff in the state [2].
Paxton said the endorsement from Trump served as a decisive factor in the race. He said the political momentum generated by that support was the most powerful force in politics [5].
“His endorsement was the most powerful force in politics.”
The defeat of an incumbent senator by a Trump-endorsed challenger signals a continuing consolidation of the MAGA movement's influence over the Texas Republican primary process. By replacing a long-standing incumbent with a candidate explicitly aligned with Donald Trump, the GOP's internal power structure in Texas is shifting toward a more populist, confrontational legal and political strategy.
