Texas Attorney General Ken Paxton easily defeated Senator John Cornyn in a Republican run-off primary on Tuesday night.
While the outcome had been expected for weeks, it marks a stunning defeat for an incumbent who served in Congress for 23 years, including 12 years as a high-ranking member of the Senate Republican leadership team.
The bruising contest set a record for the most expensive Senate primary campaign in US history.
It also sets up what will be a closely watched contest in November's general election between Paxton and his Democratic opponent, state legislator James Talarico.
The outcome of that race will help determine whether Democrats can win back control of the US Senate for the final two years of Donald Trump's presidency. Many Democrats have viewed Paxton as the weaker of the two candidates and relish what they believe is an opportunity to flip a Senate seat in a state with a long history of electing Republicans.
Seemingly confident of his impending primary victory, Paxton, 62, already has begun pivoting toward his general election matchup, airing television adverts over the past week attacking his opponent as a left-wing extremist.
Polls indicated a tight race in a state that hasn't elected a Democrat to the Senate since 1988.
It's been 46 years since at least two incumbent senators were felled by voters in their own party in the same election cycle. Just 10 days ago, Louisiana senator Bill Cassidy failed to even reach his party's run-off primary, finishing behind two Republican challengers – the political equivalent of lightning striking in the same spot twice.
Both Cornyn and Cassidy faced off against candidates endorsed by President Donald Trump. But that's where the similarities largely end.
Unlike Cassidy, who voted to convict Trump during his 2021 Senate impeachment trial, Cornyn was a party loyalist who touted his ties to the president. While he was slow to endorse Trump's 2024 re-election bid, he faithfully toed the Republican line throughout his time in the Senate.
In the first round of balloting in March, he finished slightly ahead of Paxton, 42.5% to 40.8%, but short of the 50% necessary to avoid a run-off.
The day after that vote, it appeared that Trump might endorse Cornyn – a popular figure among Senate Republicans due to his prolific fundraising and prior leadership in the chamber.
That endorsement never came, however. Paxton, while beset with personal and political scandals over the years, was a favourite among Trump's populist base in Texas. He campaigned against the 74-year-old Cornyn as too old, too timid, too aligned with the political establishment and too out-of-touch with Texas conservatives.
Last week, after it appeared increasingly likely that Paxton would defeat Cornyn despite being outspent by a 9-to-1 margin, Trump endorsed the challenger. Trump has accused Cornyn of being "very disloyal" to him on social media, arguing he did not fight hard enough to save Trump's voting reform legislation.
Paxton's victory might be characterised as another example of the strength of Trump's endorsement. Trump has seen several Republicans he endorsed beat out his critics in primaries, including Cassidy in Louisiana and Representative Thomas Massie in Kentucky.
But Tuesday night, the timing suggests this is a case of Trump following his base - which, at least in Texas, is still hungry for firebrand populist conservatives and wary of longtime Washington politicians.
If the Cassidy defeat showed Trump still can sway Republican voters, the Texas matchup hints that the impulses motivating Trump's base can at times be larger than – and distinct – from him.
While the Republican Senate runoff was the marquee matchup in Texas, there were several notable contests also on the ballot.
In the race for the Republican nomination to replace Paxton as attorney general, Congressman Chip Roy – a small-government conservative who sometimes drew Trump's ire for voting against his party in the House – was defeated by state Senator Mayes Middleton.
Unlike the Senate primary, however, Trump didn't offer his endorsement – although he had called for Roy to be challenged for his congressional seat in 2023.
Trump's endorsement power was on display farther down the Republican side of the ballot, however. In the solidly conservative 9th District, Trump-backed Army veteran Alex Mealer defeated state Representative Briscoe Cain, who had been endorsed by Texas Republican Governor Greg Abbott. And in the 35th, Trump's Carlos De La Cruz bested Abbott's John Lujan.
In the runoff for the Democratic nomination in the 35th House district, which stretches southeast from the outskirts of San Antonio, sheriff's deputy Johnny Garcia defeated sex-therapist Maureen Galindo.
Galindo, a little-known candidate, had finished slightly ahead in March's balloting, but she became a source of national controversy for suggesting that American Zionists should be held in immigration detention camps.
Galindo, whose campaign appears to have been funded in part by a conservative-affiliated group, was condemned by Democrats across the party's political spectrum. Two House Democrats, Josh Gottheimer of New Jersey and Jared Moscowitz of Florida, said they would force daily votes to expel her from Congress if she were elected.
With Garcia's victory, the Democrats avoided nominating a divisive candidate in a congressional district that, while tilting towards Republicans, could be winnable for their party.
Several other Democratic runoff contests pitted current and former members of Congress against each other – a reflection of the scramble created after the Republican-controlled state legislature redrew congressional lines last year to net more House seats for its party.
In the Houston-centered 18th District, 38-year-old, one-term Congressman Christian Menefee defeated 78-year-old Al Green, who had served in the House since 2005.
Green built a reputation as a liberal firebrand. He was removed from Trump's past two congressional addresses for protesting and regularly introduced articles of impeachment against Republican presidents.
Green was targeted by Fairshake, a cryptocurrency-backed group, which spent approximately $6m to oust the longtime congressman, who had been a critic of the industry.
In the 33rd District, near Dallas, former Congressman Colin Allred – the Democratic nominee for Senate in 2024 – defeated current Congresswoman Julie Johnson.
It was a measure of revenge for Congresswoman Jasmine Crockett, who was defeated by Talarico for the Democratic Senate nomination in March. She had backed Allred, while Johnson was Talarico's choice.
Democrats may be encouraged by the Paxton victory, sensing that his past scandals make him a more vulnerable opponent than the deep-pocketed Cornyn. But given that Texas has long been considered reliably Republican territory, they will have to quickly pull together if Talarico hopes to win in November.
Madeline Halpert contributed to this report.
