Facing possible primary challenge from Trump ally, long-serving senator gets backing of leader Thune

Thune, who topped Cornyn last year in the Senate GOP race to succeed longtime leader Mitch McConnell, emphasized that his one-time rival "was tireless and instrumental in building our majority. We need to keep him in the Senate & in the fight to deliver on President Trump's agenda."

"I can't think of a single thing he's accomplished for our state or even for the country," Paxton said in a September 2023 interview on the Fox News Channel. "Somebody needs to step up and run against this guy," adding, "everything's on the table for me."

And in a Fox News Digital interview earlier this year, Paxton said that he's "looking potentially at the U.S. Senate."

While Paxton is very popular with the conservative base of the party, political strategists note that toppling Cornyn in a GOP primary would likely be a very expensive proposition, and it's not clear if Paxton could raise the money needed for victory.

Paxton has claimed Cornyn does not represent the conservative values of Texans and accused him of not being an ally of Trump.

He has also regularly labeled Cornyn a "RINO," a "Republican in name only" and an insult MAGA and "America First" Republicans have regularly used to criticize more mainstream or establishment members of the GOP.

Since Trump returned to the White House two months ago, Cornyn has been supportive of the president's cabinet nominees and agenda.

And in the senator's campaign launch video, the announcer highlights that during Trump's first term in office, "Texas Sen. John Cornyn had his back."

"Now I'm running for re-election and asking for your support so President Trump and I can pick up where we left off," Cornyn says to camera in the video.

Cornyn is a former state senator, former Texas Supreme Court justice, and former state attorney general, who first won election to the U.S. Senate in 2002.

Fox News' Peter Pinedo contributed to this report