Published by TrenBuzz.com | May 27, 2026
Key Points at a Glance – Ken Paxton Becomes First Challenger to Defeat a Sitting Texas Senator
- Ken Paxton defeated John Cornyn with 63.4% of votes in Tuesday’s Texas GOP Senate runoff.
- Trump endorsed Paxton on May 19, just one week before voting, calling Cornyn disloyal “when times were tough.”
- Paxton is the first challenger ever to defeat a sitting Texas US senator in a Republican primary.
- Total combined ad spending in the race reached $135 million over 13 months.
- Paxton will face Democrat James Talarico in November in what could be a competitive general election.
- Senate Republicans including Majority Leader Thune backed Cornyn heavily and lost decisively.
It took three decades. Four Senate terms. And one Trump endorsement to end it all in a single night.
Attorney General Ken Paxton won the Republican primary runoff for US Senate Tuesday, ending over three decades of Senator John Cornyn’s electoral dominance in what amounts to a watershed moment for GOP politics in Texas.
“Tonight we just sent a Texas-sized message to Washington,” Paxton told cheering supporters at his Plano watch party. “Today, change was on the ballot. Change won.”
Trump’s Endorsement Changed Everything Instantly
Trump threw his weight behind Paxton citing Paxton’s loyalty and Cornyn’s lack thereof “when times were tough.” The decision went against the advice of Senate Majority Leader John Thune and the Republican political machine in Washington, who spent tens of millions of dollars boosting Cornyn.
On Polymarket, Paxton jumped to a 96% chance of winning immediately after the Trump endorsement on May 19. Just days earlier, on May 18, Paxton had only a 63.7% chance of winning the nomination. Cornyn had been at 37.2%.
The General Election Warning Ahead
Senate Republicans are bracing for an expensive general election in Texas. Paxton’s numerous scandals, including his impeachment by the Texas House in 2023 and federal investigations, give Democrats a significant attack surface in the November race against James Talarico.
“Paxton has spent his entire political career courting the base voters in the Republican Party,” said Joshua Blank of the Texas Politics Project. “And it is many of these hardcore Republicans who have been most skeptical of John Cornyn.”
Texas just sent its message to Washington loud and clear. Whether that message helps or hurts Republicans in November is the question every GOP strategist is asking right now.
Disclaimer: This article is for general informational and news reporting purposes only. All election results, quotes, and polling data are sourced from the Texas Tribune, Houston Public Media, Fox News, and NBC News as of May 26, 2026. Results shown are unofficial pending final certification. TrenBuzz.com does not endorse any political candidate or party. Readers are encouraged to follow official Texas Secretary of State sources for certified results.