Texas Attorney General Ken Paxton won the Republican nomination for the United States Senate on Tuesday, defeating four-term Senator John Cornyn.

According to results reported by The Associated Press news agency, Paxton won with about 64 percent of the vote, while Cornyn received about 36 percent, a margin of roughly 28 percentage points.

US President Donald Trump endorsed Paxton last week, calling him a “true MAGA warrior”. The loss makes Cornyn, first elected in 2002, the first-ever Republican senator from Texas to lose his party’s nomination for re-election.

Here is what we know:

Paxton calls Trump endorsement ‘most powerful force in politics’

Paxton’s victory added to a growing list of Trump-backed primary wins before the 2026 midterms.

Cornyn, who served in the Senate for more than 20 years and was once part of the Republican leadership in Congress, is widely regarded as a traditional establishment Republican. Despite support from chief donors and senior party figures, he struggled to win over Trump’s supporters.

For months, Cornyn tried to show he supported Trump and his agenda. He highlighted his voting record with Trump, backed parts of Trump’s immigration plans and changed his position on some Senate rules to support voting restrictions backed by the president.

But Trump continued to criticise Cornyn, accusing him of being “very disloyal” after the senator questioned Trump’s political future in 2023 and waited months before endorsing his 2024 campaign.

Trump’s endorsement of Paxton last week changed the race and helped make Cornyn the latest Republican incumbent to lose to a Trump-backed challenger.

“Tonight, we’ve come up short,” Cornyn told supporters after the race was called, while promising to continue supporting Republican candidates.

The defeat makes Cornyn the first Republican senator from Texas to lose a primary while seeking re-election, a result likely to end his Senate career.

Paxton celebrated the victory and called Trump’s endorsement “the most powerful force in politics”.

The Texas race follows other recent defeats of Republican incumbents opposed by Trump, including Louisiana Senator Bill Cassidy and Kentucky Representative Thomas Massie.

Some Republicans, however, worry Paxton could struggle in the November midterm elections because of a series of scandals and legal controversies that have followed him for years, including corruption allegations, impeachment proceedings and securities fraud charges. Paxton was impeached in 2023 over accusations that he abused his office to benefit a donor. However, the Texas Senate acquitted him, allowing him to return to office.

“Many Republicans believe that this win will actually give Donald Trump a headache,” said Al Jazeera’s Alan Fisher, reporting from Washington, DC. “That Paxton is too tainted, too extreme to connect with ordinary Texas voters.”

Paxton will now face Democratic state Representative James Talarico, whose campaign has focused on centrist and independent voters.

Democrats see chance to make Texas Senate race competitive

Democrats are hoping Paxton’s nomination could turn Texas into a more competitive battleground in November, despite the state’s long Republican streak in Senate races.

Talarico has sought to present himself as a centrist alternative, focusing his campaign on corruption, public education and economic issues.

Democrats also point to demographic changes across Texas, including growth among Hispanic, Asian and multiracial communities, as a sign the state is becoming more politically competitive.

The Cook Political Report recently shifted Texas from “likely Republican” to “lean Republican”, reflecting expectations of a closer race.

“Without a shadow of a doubt, I will be the Democrats’ number one target in November,” Paxton said after winning the race.

The candidate also predicted that Talarico is “going to raise more money than any Democrat in America”, and urged his followers to donate to his campaign.

“If Republicans lose this state, we lose the country,” Paxton warned.

Within minutes of Paxton being declared the winner of the Republican primary run-off for the US Senate, Talarico called him “the most corrupt politician in America” in a social media post.

“He embodies the broken system we’re running against,” Talarico wrote on X.

In another post, he invited Cornyn’s supporters to vote for him. “You have a place in our campaign,” Talarico wrote.

Veteran Democrat Al Green loses primary to younger challenger

Longtime Democratic Congressman Al Green has lost his primary run-off to younger challenger Christian Menefee, marking a key generational shift in one of Texas’s safest Democratic districts.

Menefee will now begin his fourth election campaign in roughly seven months. He first entered the race in a November 2025 special election to replace former Representative Sylvester Turner, who died earlier that year. The contest advanced to a January run-off, which Menefee won before being sworn into Congress.

Menefee then launched a bid for a full term in the March 3 Democratic primary, emerging from a crowded field to face veteran Congressman Al Green in Tuesday’s run-off.

With the victory, Menefee is expected to head into November’s general election as the strong favourite in the heavily Democratic district.

The race also drew national attention because of heavy spending by Fairshake, a pro-cryptocurrency super PAC that backed Menefee and targeted Green over his opposition to parts of the crypto industry’s agenda.

Fairshake spent millions of dollars on the run-off, with Fairshake spokesperson Geoff Vetter arguing the group had been “the difference-maker” in the contest.

Colin Allred is set to return to his former House seat

Former US Representative Colin Allred won a closely watched Democratic primary run-off on Tuesday, putting him on track to return to Congress after losing his 2024 Senate race against Republican Senator Ted Cruz.

Allred left the House in 2024 to challenge Cruz in one of the country’s biggest Senate races, but Democrats failed to flip the seat.

He later prepared for another Senate run before dropping out after fellow Democrat Jasmine Crockett entered the race. Instead, Allred decided to run again for the North Texas congressional seat he had held for six years.

In Tuesday’s run-off, Allred defeated Representative Julie Johnson, who had won the seat after he stepped down to run for Senate.

The race became one of the state’s most bitter Democratic contests, with both candidates attacking each other over money, ethics and personal wealth.

Allred criticised Johnson over stock trades she made while in office, including investments linked to Palantir Technologies, a data company with ties to the Trump administration.

Johnson, meanwhile, accused Allred of being “only out for himself” and attacked his personal wealth.

The race also exposed divisions among Democrats over money and influence in politics.

Democrats back Johnny Garcia after bitter Texas run-off

Garcia defeated Maureen Galindo in the Democratic primary run-off for Texas’s 35th congressional district near San Antonio, after national Democrats strongly intervened in the race.

Democratic leaders had worked to stop Galindo from winning the nomination because of comments widely condemned as anti-Semitic. Galindo had posted remarks about “American Zionists”, repeated conspiracy theories about Jewish influence in politics and media, and referred to Jews as the “synagogue of Satan”, according to local media reports.

Senior Democrats, including House Minority Leader Hakeem Jeffries and Representative Suzan DelBene, publicly opposed Galindo’s candidacy. Representative Alexandria Ocasio-Cortez called Galindo’s comments “disgusting” and said they had “no place” in Democratic politics.

The race gained national attention because Republicans recently redrew the district in a way aimed at helping their party win more seats. Democrats still believe the district could remain competitive in November, but feared Galindo’s comments would hurt their chances in the general election.

After Garcia’s victory, the Democratic-aligned House Majority PAC accused Republicans of secretly helping Galindo’s campaign through outside groups in an effort to weaken Democrats before November.