WASHINGTON — After months of sitting on the sidelines, President Trump has formally endorsed Texas Attorney General Ken Paxton over incumbent Sen. John Cornyn in what has become the most expensive Senate primary in US history.

The move is a massive blow to Cornyn (R-Texas), who was fighting for his political life and had been trailing the firebrand state AG in most polling as the GOP braces for a slugfest against state Rep. James Talarico (D-50th Dist.) in the general election.

“I know Ken well, have seen him tested at the highest and most difficult levels, and he is a WINNER! Ken is a Strong Supporter of TERMINATING THE FILIBUSTER and, very importantly, THE SAVE AMERICA ACT,” Trump noted in his Truth Social endorsement.

“Ken is a true MAGA Warrior who has ALWAYS delivered for Texas, and will continue to do so in the United States Senate,” he went on. “Ken Paxton has gone through a lot, in many cases, very unfairly, but he is a Fighter, and knows how to WIN. Our Country needs Fighters, and also Loyalty to the Cause of Greatness.”

During the scramble to get Trump’s endorsement, Cornyn had backed calls to weaken the filibuster and championed the SAVE America Act to require proof of citizenship to vote, among other conservative wishlist items. On Monday, Cornyn told reporters he thought “that ship has finally sailed” for Trump to make an endorsement.

Republican establishment figures had universally begged Trump to throw his weight behind Cornyn, including Senate Majority Leader John Thune (R-SD), the National Republican Senatorial Committee, and scores of senators.

Even Trump’s 2024 co-campaign manager, Chris LaCivita, had backed Cornyn and pushed the president to support him.

The argument was that Paxton would face a tougher battle in the general election due to his past scandals, making the Texas Senate race a money pit that would divert resources from elsewhere.

Paxton currently has a 3.2 percentage-point edge over Cornyn in the latest RealClearPolitics aggregate of polls. 

But Paxton, who polls show would face a tough general election matchup against Talarico, had considerable clout with the MAGA base, despite his scandals.

Back in 2015, the Texas AG was indicted on securities fraud charges from before he assumed that role. Those charges were later dismissed in a pretrial diversion agreement.

In 2023, he was impeached over allegations that he obstructed justice in that securities fraud case, gave preferential treatment to a donor, made false statements against whistleblowers, and misappropriated public resources, among other concerns.

During the trial, he was suspended from his duties as state AG, but ultimately, he survived impeachment proceedings in the state Senate in a narrow 16–14 vote.

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Despite the baggage against him, Paxton continued to win favor with the GOP base by throwing red meat, having backed Trump’s push to challenge the 2020 election.

Paxton also took legal action against the Biden administration at least 106 times.

Cornyn, who served as a Texas Supreme Court justice between 1991 and 1997, then as state AG from 1999 through 2002, previously suggested that Trump shouldn’t run for re-election in the 2024 cycle due to the legal issues he faced.

“John Cornyn is a good man, and I worked well with him, but he was not supportive of me when times were tough and, despite having the Most Successful Economy in the History of our Country during my First Term,” Trump said of the incumbent senator. 

During the tough primary process, Cornyn tried to fling red meat at the base, including through the Defeat Sharia Law Act and raising concerns about the potential for a biotech firm to usher in an age of designer babies.

Before the initial March Texas Senate primary, reports and rumors came out that Trump intended to endorse Cornyn.

Ultimately, Trump declined to do so at that time and was reportedly agitated about the leak.

Republican Texas Gov. Greg Abbott and Sen. Ted Cruz (R-Texas) have remained neutral in the Senate race.

A slew of Republican senators openly groaned about Trump’s endorsement, with Sen. Susan Collins (R-Maine) knocking Paxton as “ethically challenged” and others complaining about the burden it will put on the party heading into the general election.

“I think Paxton can win, yeah, but I think it’d be three times more expensive,” Sen. Lindsey Graham (R-SC) told reporters. “We’ve got to raise a lot more money now.”

“How does that help strengthen the president’s hand when we lose a state like Texas?” Sen. Lisa Murkowski (R-Alaska) lamented, noting the move “puts that seat in jeopardy.”

Despite the now-stiff odds of eking out a win, Cornyn remained defiant and vowed to power through the runoff. 

“I have worked closely with President Trump through both of his Presidential terms and voted with him more than 99% of the time. He has consistently called me a friend in this race,” Cornyn posted on X after Trump’s endorsement. 

“It is now time for Texas Republican voters to decide if they want a strong nominee to help our GOP candidates down ballot and defeat Talarico in November, or a weak nominee who jeopardizes everything we care about.”