Houston (AFP) - Donald Trump on Wednesday hailed a decisive win for his favored candidate in a bitter Senate primary runoff in Texas, as scandal-plagued Ken Paxton’s victory further cemented the US president’s grip on the Republican Party.

Paxton’s resounding defeat on Tuesday of incumbent Senator John Cornyn underscored Trump’s continued power to make or break Republican political careers – even as lawmakers on Capitol Hill begin to rebel over the Iran war, his White House ballroom project and a compensation fund for his allies.

Cornyn, a four-term senator and former Republican whip, began the year as the establishment favorite.

Trump’s late endorsement transformed the race, giving Paxton a decisive boost and leaving Cornyn as the latest Republican incumbent punished after falling out of step with the president.

In an early Wednesday post on his Truth Social platform, Trump congratulated Paxton on his “tremendous win” and predicted he would “become a fantastic, common sense Senator, one who is respected by all.”

The result once again exposed the central tension facing Republicans ahead of November’s midterm elections: a Trump endorsement can be decisive in a primary, but the president often favors hard-right candidates whom party strategists fear could prove weaker in a general election.

Paxton, Texas’s attorney general, has survived years of legal, ethical and personal scandal, including a 2023 impeachment by the Republican-led Texas House, allegations of bribery and misconduct, and a messy divorce.

The 63-year-old was acquitted by the Texas Senate after his impeachment trial and has long cast the allegations against him as politically motivated.

Cornyn by contrast was a straight-laced institutional conservative who had represented Texas in the Senate since 2002 and built deep ties with the state’s donor class and Republican leadership in Washington.

- ‘Most powerful force’ -

Paxton won easily, with more than 63 percent of the vote, the official count showed.

At a victory party Tuesday night, he thanked Trump.

“When everyone in Washington told him to abandon me and abandon the people of Texas, he didn’t listen,” Paxton said.

He called Trump’s endorsement “the most powerful force in politics.”

In his Truth Social post Wednesday, Trump turned his attention to Paxton’s Democratic opponent in the November elections, James Talarico, saying he “may be the worst TEXAS candidate I have ever seen” and attacking his liberal policy stances.

Trump also said he would stage “nice, big, beautiful rallies for Ken.”

Talarico, a state representative and rising national figure, has raised large sums of money and argues that both Republicans represent a broken political system tilted toward wealthy donors.

Republicans still start as favorites in Texas, which Trump carried by nearly 14 points in 2024.

But Democrats see Paxton as the riskier nominee and believe his baggage could help them make a serious play for a statewide breakthrough.

Paxton’s win is likely to deepen unease among Senate Republicans, many of whom had urged Trump to support Cornyn and now fear the party will have to spend heavily defending a seat that should not normally be competitive.

Senate Majority Leader John Thune warned last week that taking on incumbent senators can have consequences, saying Trump’s interventions could make advancing his agenda “more complicated.”

That concern has already begun playing out on Capitol Hill, where some Republicans have broken with Trump over Iran war powers and other issues.

For Trump, however, the Texas result added another victory to a primary-season revenge tour that has already helped oust Louisiana Senator Bill Cassidy, who voted to impeach Trump; Kentucky Congressman Thomas Massie, who backed releasing the so-called Epstein files; and Indiana state lawmakers who resisted his redistricting demands.

In his concession speech, Cornyn quoted scripture, saying: “I fought the good fight, I finished the race, and I’ve kept the faith.”

In an X post after Cornyn’s speech, Talarico thanked the senator for representing Texas.

“We don’t agree on everything, but we both still believe in public service,” Talarico said. “To Senator Cornyn’s supporters: you have a place in our campaign.”