Elections · Government · Legislative Process·May 26, 2026
Trump ends John Cornyn's 24-year Senate career with Paxton endorsement
A presidential endorsement just ended a 24-year Senate career.
On May 26, 2026, Texas Attorney General Ken Paxton defeated four-term incumbent Sen. John Cornyn in the Republican primary runoff for Texas's U.S. SenateThe upper chamber of Congress with 100 members (two per state) serving six-year staggered terms.Key ConceptSenateThe upper chamber of Congress with 100 members (two per state) serving six-year staggered terms.Open concept seat. Paxton won by more than 20 points statewide, carrying Tarrant County, a Fort Worth suburb Cornyn had won 43%-38% in March, by a 59%-41% margin on runoff night. The result made Cornyn the first Texas U.S. senator to lose a primary since Lloyd Bentsen defeated Ralph Yarborough in 1970.
Cornyn had served in the SenateThe upper chamber of Congress with 100 members (two per state) serving six-year staggered terms.Key ConceptSenateThe upper chamber of Congress with 100 members (two per state) serving six-year staggered terms.Open concept since January 2002, won four consecutive terms, and was widely considered one of the chamber's most institutionally powerful members. His defeat sent an immediate signal to every Republican senator: incumbency offers no protection when the president decides they're disloyal.
The race turned on a single Truth Social post. On May 19, 2026, seven days before the vote, Trump declared Paxton 'a true MAGA Warrior who has ALWAYS delivered for Texas' and attacked Cornyn for failing to be 'supportive of me when times were tough.' The 657-word endorsement caused an immediate market collapse for Cornyn.
Kalshi, the prediction market, moved Cornyn from 37% to 10% overnight. Polymarket reached 96% Paxton by election eve. A Quantus Insights poll taken in the final days showed Paxton up 9.3 points. Earlier University of Houston polling had the gap at 10 to 22 points among likely runoff voters.
The weapon Trump and Paxton wielded against Cornyn was the Bipartisan Safer Communities Act, the gun safety legislation Cornyn co-authored with Democratic Sen. Chris Murphy after the Uvalde school shooting in May 2022. The law expanded background checks for gun buyers under 21, funded state red flag laws, and earmarked $11 billion for mental health services.
Trump called the bill a first step to 'TAKE YOUR GUNS AWAY' and labeled Cornyn a 'RINO.' Paxton attacked Cornyn as an 'anti-gun establishment politician' throughout the campaign. The gun bill became the defining liability that Cornyn's $90 million ad campaign couldn't overcome.
John Cornyn served as Senate Republican Whip from 2013 to 2019, the chamber's second-ranking position, after chairing the National Republican Senatorial Committee from 2009 to 2013. In November 2024, he ran for Senate Majority Leader but lost to John Thune 29-24 in a closed-door Republican caucus vote. As of May 2026, he held no formal Senate leadership role.
The day before the runoff, Trump posted that Cornyn had been 'VERY disloyal,' escalating from the endorsement post's more measured criticism. With Trump publicly labeling the sitting senator disloyal on election eve, Cornyn's campaign had no effective counter.
Ken Paxton has been Texas Attorney General since 2015. A Collin County grand jury indicted him in July 2015 on two counts of first-degree securities fraud for soliciting investors in Servergy Inc. without disclosing he was paid to promote its stock. In May 2023, the Texas House impeached him 121-23 on charges including bribery, obstruction, and misuse of public resources for a political donor.
The Texas Senate acquitted Paxton 16-14 in September 2023. He reached a deferred prosecution agreement in March 2024: Paxton paid $300,000 in restitution, completed 200 hours of community service, and finished 30 hours of legal ethics training. The securities fraud charges were officially dismissed on June 18, 2025.
Democratic state Rep. James Talarico won the March 3 primary outright with 52.4% of the vote, avoiding a runoff entirely. He has served in the Texas House of Representatives since 2018, holds a master's degree in education policy from Harvard University, and spent months building donor relationships and general election infrastructure while Cornyn and Paxton attacked each other.
April 2026 polls from Texas Public Opinion Research showed Talarico leading Paxton 46%-41%. The University of Texas Texas Politics Project gave Talarico an 8-point edge in a separate survey. Cook Political Report rates the seat 'likely Republican,' but the combination of Paxton's legal record, Cornyn's warnings about electability, and Democratic overperformances in 2025-2026 special elections has made Texas a race both parties watch.
The 2026 Texas race fits a pattern Trump established across the midterm cycle. On May 16, 2026, Trump-endorsed Rep. Julia Letlow defeated Sen. Bill Cassidy in Louisiana after Cassidy had voted to convict Trump after his second impeachment. Trump's endorsement of Paxton came after months of Cornyn courting Trump's favor while refusing to commit to full loyalty.
NBC News analysis published on election day identified the 2026 cycle as Trump's systematic use of primary endorsements as loyalty tests, punishing bipartisan dealmakers and rewarding ideological alignment regardless of seniority or institutional effectiveness. Senate Republican leaders who backed Cornyn, including Majority Leader John Thune, now face the prospect of defending a Texas seat that Democrats haven't held since 1994.
Cornyn and his allies spent more than $120 million total across both rounds of the primary contest, with Cornyn's side outspending Paxton's side roughly 17-to-1 in the runoff. The spending advantage produced attack ads that saturated Texas airwaves with Paxton's corruption record, impeachment history, and legal settlements.
Cornyn's closing argument was explicit: Paxton's baggage would hand Democrats a Senate seat Texas Republicans had held for more than three decades. That argument proved irrelevant inside a Republican primary electorate where Trump's opinion outweighed financial advantage, institutional backing, and a 24-year incumbency record.
Related timeline
The Long Game: Conservative Infrastructure (1971-2025)
Arc of conservative movement infrastructure built across five decades: from the Powell Memo (1971) through Heritage, the Federalist Society, ALEC, Citizens United, Project 2025, and Trump Day 1 implementation in 2025.
Paxton defeats Cornyn in the Texas Senate runoff despite a 17-to-1 spending deficit
Main
Ken Paxton defeated incumbent Senator John Cornyn in the Texas Republican Senate runoff, winning approximately 57 percent of the vote despite being outspent 17-to-1 in the runoff alone. Cornyn spent more than $50 million in the runoff to Paxton's roughly $3 million, yet lost by a double-digit margin. The result ended Cornyn's 24-year Senate career and marked the first time a sitting senator with a leadership-tier record had been defeated in a primary by a Trump-endorsed challenger.