Texas Republicans headed to the polls Tuesday in a runoff that could end John Cornyn's 24-year Senate career, and hand the nomination to a Trump-backed attorney general who was impeached, acquitted, and divorced in the span of two years. President Trump's late endorsement of Ken Paxton has scrambled a race Cornyn once seemed poised to win, turning what was already the most expensive Senate primary in American history into a referendum on loyalty to the man in the White House.
Cornyn led Paxton in the March primary but failed to clear the majority threshold, forcing the runoff. Since then, the Associated Press reported, Cornyn and allied groups have outspent Paxton's campaign and supportive super PACs by nearly three to one, $16.5 million to $5.9 million since March 3, per ad-tracking firm AdImpact. The broader advertising blitz from the Cornyn side topped roughly $90 million since last year, most of it aimed at tearing down Paxton.
None of it may matter now.
Trump had promised to endorse immediately after the March primary. He didn't. Instead, he waited until after early voting opened last week, then posted a social media endorsement praising Paxton as a fighter and taking a direct shot at the four-term incumbent.
"Ken Paxton has gone through a lot, in many cases, very unfairly, but he is a Fighter, and knows how to win," Trump wrote. He added that Cornyn "was not supportive of me when times were tough" and was "very late in backing me."
Within 24 hours, Paxton's campaign and a pro-Paxton super PAC had new ads on the air promoting the endorsement. Newsmax reported that Trump reaffirmed his support on Sunday, calling Cornyn "VERY disloyal" in a follow-up social media post, his strongest public rebuke of the senator to date.
The timing mattered. Polling aggregates before the endorsement already showed Paxton edging ahead. The New York Post reported Paxton led by 3.2 percentage points in the latest aggregate, and that Republican establishment figures, including Senate Majority Leader John Thune and Trump's own 2024 co-campaign manager Chris LaCivita, had urged the president to back Cornyn instead.
Trump chose otherwise.
Cornyn appeared on Fox News Radio's "The Brian Kilmeade Show" on Tuesday to make his case. He did not attack Trump. He attacked the people around the race.
"There are grifters claiming that I am opposed to the president's agenda, and I think that's caused some confusion with the president himself. But I've been supportive."
Hours after the endorsement landed, Cornyn had offered a more measured response: "I know who gets to choose our senators, and it's the people of Texas." He acknowledged the endorsement would have an impact but said he wasn't giving up.
The senator's record, though, carries baggage that no ad buy can erase. In 2023, Cornyn suggested Trump could not win the presidency again, saying "time has passed him by." He was an early critic of Trump's border wall plan, a position he later reversed. Those shifts may look like pragmatism to Washington insiders. To a GOP primary electorate shaped by Trump, they look like hedging.
Sen. Lindsey Graham, speaking to the New York Post, acknowledged the stakes bluntly: "I think Paxton can win, yeah, but I think it'd be three times more expensive." The concern among Senate Republicans isn't that Paxton can't beat Democrat James Talarico in November, it's that his personal baggage will force the party to spend far more to hold a seat that should be safe.
That concern reflects broader fractures within the Senate Republican conference, where disagreements over priorities and loyalty to the White House have spilled into public view on multiple fronts this year.
Ken Paxton is not a conventional candidate. In 2023, the Texas House impeached him on corruption charges. The state Senate acquitted him. During the trial, allegations of extramarital affairs surfaced publicly. His wife later filed for divorce, citing "biblical grounds."
None of that has dented his standing with the Trump base. Texas Republican strategist Tyler Norris told the AP that Paxton's support draws from "the hardest of the hard core", voters whose loyalty to the MAGA movement is unshakable. Norris also warned that the race's negative tenor could suppress overall turnout, a dynamic that typically favors the candidate with the more motivated base.
That candidate, right now, is Paxton.
National Review noted that Paxton led in polling at 45.5 percent to Cornyn's 42.3 percent even before the endorsement dropped, and that Trump's endorsements in GOP primaries have been historically determinative. Trump already backed successful challengers to Republican incumbents in Louisiana, Kentucky, and Indiana this month alone.
Paxton's willingness to take unconventional positions has also kept him in the headlines. Earlier in the cycle, he floated an offer to exit the Senate race entirely if Congress eliminated the filibuster and passed the SAVE Act, a move that underscored his alignment with Trump's legislative priorities and put Cornyn in an awkward position.
At polling locations across the Dallas area and Plano on Tuesday, the fault line was clear. David Jacobson, a 71-year-old retiree who voted near Dallas, said Trump's endorsement tipped his decision. He noted that Cornyn "has for the most part been a strong Trump supporter" but added: "Maybe it's time for a change." Jacobson said he generally believes most politicians have stayed in office too long.
Linda Williams, voting in Plano, went the other way. She called Cornyn "the lesser of two evils" and said she voted for him for one reason: "Because Paxton is a crook." Williams was focused on electability, specifically, the risk that Paxton's scandals hand Democrats an opening against Talarico in November.
That fear is not unfounded. Democrats need a net gain of four Senate seats to reclaim the majority, and they see Texas as newly competitive if Paxton is the nominee. Talarico, a Democratic state representative, will face the runoff winner in November. Fox News reported that Cornyn himself has warned of "an incredible tsunami of Democratic funds" flowing into the state if Paxton wins the nomination.
Democrats haven't won a statewide office in Texas in decades. But the prospect of running against a candidate carrying impeachment, divorce, and affair allegations has party strategists more optimistic than they've been in years. Barack Obama recently traveled to Austin to campaign for Talarico, a sign that national Democrats are treating the general election as a real contest.
The Texas runoff fits a pattern that has defined the 2026 cycle. Trump has systematically targeted Republican incumbents he views as insufficiently loyal, and he has won. The successful challenges in Louisiana, Kentucky, and Indiana this month sent a clear message to sitting senators: cross the president, and you may face a primary opponent with his full backing.
Wayne Hamilton, former executive director of the Texas Republican Party, described the final stretch to Newsmax as a "slug fest, with the campaigns and third-party groups slugging it out." But the dynamic shifted decisively once Trump weighed in. Cornyn's massive spending advantage, the kind of financial edge that usually buries a challenger, has been neutralized by a single social media post from the president.
Trump's intervention in Texas is not limited to the Senate race. He recently endorsed Brandon Herrera in the state's 23rd Congressional District after the incumbent exited over a personal scandal, reinforcing his role as the party's gatekeeper at every level.
If Cornyn loses Tuesday, he will be the first Republican senator in Texas history to seek his party's nomination and fail. That distinction would mark the end of a career that spanned four terms, two stints as Senate whip, and a long evolution from establishment dealmaker to reluctant Trump ally, an evolution that, in the end, may not have gone far enough or fast enough.
Tuesday's ballot in Texas extends beyond the Senate. Democrats are holding House runoffs in three districts reshaped by Republican-led redistricting last year. In Houston's 18th District, newly elected Representative Christian Menefee faces veteran Rep. Al Green after the legislature redrew the map and forced two incumbents into the same race. In the Dallas-area 33rd District, Colin Allred, who lost a 2024 Senate bid against Ted Cruz, is running against Rep. Julie Johnson. Near San Antonio, the 35th District runoff between Maureen Galindo and Johnny Garcia has drawn attention because Democratic leaders are actively trying to block Galindo, who has expressed antisemitic views, from winning the nomination.
The 35th District was drawn by Republicans to favor the GOP, but Democrats believe it remains within reach. The 18th and 33rd districts overwhelmingly support Democrats, making those races primarily about which Democrat will hold the seat.
But the headline race is the Senate. And in that race, the question is no longer whether Cornyn's $90 million war chest can hold off a challenger with a fraction of the resources. The question is whether any amount of money can outweigh a presidential endorsement in a Republican primary.
In today's GOP, that question answers itself.
