Republican Texas Senate candidate Ken Paxton speaks with supporters at a watch party on March 3, 2026 in Dallas, Texas. Paxton and incumbent John Cornyn will face off again in a runoff.
Sergio Flores | Getty Images
President Donald Trump endorsed Texas Attorney General Ken Paxton in Tuesday’s Republican Senate primary runoff, endorsing a hardline ally and dealing a major blow to incumbent Sen. John Cornyn a week before Election Day.
The endorsement is a big boost for Paxton in one of the most closely watched Senate primaries in the Republican Party, testing President Trump’s grip on Republican voters and the strength of the Senate Republican establishment.
“Ken is a true MAGA warrior who has always served Texas and will continue to do so in the United States Senate. He will work tirelessly to continue the great growth of our economy, cutting taxes and regulating,” Trump said in a post on Truth Social. “Ken Paxton has faced great injustice on many occasions, but he is a fighter and he knows how to win. Our country needs fighters and we need loyalty to a great cause.”
The May 26 runoff will pit Paxton, a longtime ally of President Trump, against Cornyn, the incumbent who has served four terms in the Senate since 2003. Early voting begins Monday and runs through Friday.
“I am extremely honored to receive President Trump’s full and complete support,” Paxton posted on X in response to the endorsement. “No one has fought harder for the American people than President Trump, and I look forward to defending his America First policies in the Senate!”
Trump’s influence
The Texas race is the latest example of President Trump’s move to influence Republican primaries, punishing lawmakers he deems insufficiently loyal and rewarding candidates aligned with his political campaign.
Sen. John Cornyn (R-Texas) confirmed to reporters that he will face a runoff election against Texas Attorney General Ken Paxton in the U.S. Senate race following the Texas Republican primary on March 3, 2026 at the Austin Marriott Downtown, Texas.
Sarah Diggins Austin American politician | Hearst Newspapers | Getty Images
“John Cornyn is a good man and I worked well with him, but even though my first term was the most economically successful in the history of our country and I accomplished so much more, he didn’t support me during tough times,” Trump wrote.
In response, Cornyn posted on X that he “worked closely with President Trump throughout his presidential term and voted for President Trump over 99% of the time.”
“He has called me a friend throughout this campaign. The time has come for Republican voters in Texas to decide now whether they want a strong candidate who will help turn out Republican votes and defeat Talarico in November, or whether they want a weak candidate who will jeopardize everything we care about. I have faith in Texas Republican voters,” he continued, referring to Democratic candidate James Talarico.
This is the third major Republican primary in a short period of time in which President Trump has exerted influence.
President Trump helped prevent the re-election of Sen. Bill Cassidy, R-Louisiana, who was impeached for the second time, and is endorsing Ed Gullane, a former Navy SEAL who is running against Rep. Thomas Massey (R-Kentucky) in Tuesday’s Republican primary. Massey has frequently broken with Trump and the House Republican leadership.
These elections served as a referendum on President Trump’s control over the Republican Party ahead of the 2026 midterm elections. Although President Trump’s overall approval ratings have declined, he remains strongly popular among Republican voters, and his support has been a major force in the primaries. Mr. Trump has used the power of his support as a tool to create incentives for political loyalty.
“I think the message people should take from this is that you basically have to serve the people who sent you. If you don’t, you’re going to be out of step with your voters,” Vice President J.D. Vance said at a White House press conference after the endorsement.
Senate Republicans’ concerns about Cornyn’s snub
Senate Republicans have warned that Mr. Paxton could be a more difficult and costly general election candidate than Mr. Cornyn.
Sen. Lindsey Graham, R-S.C., said Trump’s endorsement of Paxton could make the race “three times more expensive” for Republicans.
“I like Sen. Cornyn,” Graham told reporters at the Capitol. “If Paxton wins the primary, I’ll support him. But you don’t have to be a rocket scientist to understand that there’s a path for Paxton there, but it’s more uphill. And it’s going to cost more.”
Sen. Lisa Murkowski (R-Alaska) was blunt, calling Cornyn a “great senator” who has worked with President Trump on his policies.
“The fact that the president chooses to support a candidate who will probably struggle hard in the popular vote rather than Sen. Cornyn is troubling,” Murkowski said.
general election
In the final stretch before Election Day, Cornyn emphasized his support for Trump, writing on Monday’s X that Trump’s turnout was 99.3%. Mr. Cornyn is relying on the support of the Senate Republican leadership and outside allies, who have spent more than $60 million to protect him, according to Reuters.
Meanwhile, Mr. Paxton has sought to cast Mr. Cornyn as a monster of the Washington establishment, while Mr. Cornyn has attacked Mr. Paxton as unfit for office, pointing to years of legal and political controversy, including his 2023 impeachment by the Texas House of Representatives. Paxton was later acquitted by the Texas Senate.
According to opinion polls, the two are in a close race.
A statewide poll conducted from April 28 to May 1 by the University of Houston’s Hobby School of Public Affairs found Mr. Paxton leading Mr. Cornyn 48% to 45% among likely runoff voters, just outside the poll’s margin of error.
The winner of the runoff will face Talarico in November.
Texas Senate candidate James Talarico (D-Texas) speaks at a campaign rally in Houston, Texas on March 2, 2026. Talarico is traveling to various locations around the state in preparation for tomorrow’s primary election.
Daniel Villasana | Getty Images
Talarico, a 37-year-old state representative, defeated Rep. Jasmine Crockett in the Democratic primary in March and has a strong fundraising record, with more than $27 million raised in the first quarter, according to her campaign.
“We already know who we’re up against: billionaire mega-donors and their corrupt political system,” Talarico said in a statement after announcing his support. “For decades, John Cornyn and Ken Paxton have epitomized broken politics that enrich wealthy donors and drive up costs for the rest of the nation.”
“Our movement to take back Texas for working people goes beyond party politics, because the biggest battle in this country is not left versus right, but top versus bottom,” Talarico said.
Republicans still have the advantage of holding the Texas seat, but Democrats say the Republican primary could open the door.
Talarico is in a close race against both Republicans, according to a Texas Southern University poll released Monday, with Cornyn leading Talarico 45% to 44% and Paxton and Talarico tied at 45%.
Trump won Texas by nearly 14 percentage points in 2024.
—CNBC’s Justin Papp contributed to this report.
