WASHINGTON — President Donald Trump has endorsed Texas Attorney General Ken Paxton in his bid for the U.S. Senate, dealing a blow to Sen. John Cornyn and to Senate Republican leaders who had pleaded with the president to stand by the incumbent.“Ken Paxton has my Complete and Total Endorsement to be the next United States Senator from the Great State of Texas – KEN PAXTON WILL NEVER LET YOU DOWN!” Trump posted Tuesday on his social media site, Truth Social.Paxton and Cornyn have been aggressively competing for Trump’s support for months, a coveted endorsement that goes far in a state Trump won by 14 percentage points in 2024. Both have tied themselves to the president, but Paxton has campaigned to the right of Cornyn, casting himself as more of a die-hard Trump loyalist. It appears to have paid off. Even Cornyn’s humiliating proposal last week to rename a Texas highway for Trump wasn’t enough to prove his loyalty to the president.The two will face each other in a primary runoff set for May 26.Cornyn signaled Monday that he didn’t expect to get Trump’s endorsement: “I think that ship has finally sailed,” he told local reporters after casting his ballot in Austin during early voting.After the president’s announcement, Cornyn emphasized on social media that he’s voted with Trump “more than 99% of the time.”“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,” said the Texas senator. “I trust the Republican voters of Texas.”Paxton, meanwhile, said in a Tuesday interview on “The Charlie Kirk Show” that having Trump’s support is the biggest boost any candidate could hope for.“We all know that Donald Trump’s endorsement is the most significant endorsement in the country and maybe the most significant endorsement in my lifetime,” Paxton said.President Donald Trump has endorsed Texas Attorney General Ken Paxton (above) in his Senate bid, a blow to longtime Sen. John Cornyn.via Associated PressDemocrats, who nominated state Rep. James Talarico, have been salivating at the chance to take on Paxton in November.Unlike Cornyn, the attorney general has a history of scandal that makes him an easier political target. The GOP will potentially be forced to spend tens of millions of dollars to defend a Senate seat that it historically hasn’t had to worry much about.“Republicans are watching $100 million circle down the drain before their eyes as Donald Trump rejects their year of begging him to bail out John Cornyn,” Maeve Coyle, a spokesperson for the Democratic Senatorial Campaign Committee, said in a statement.“While the Texas GOP has been embroiled in a ‘bitter,’ ‘costly intraparty war’ that has fractured their base and left them drained of resources, Democratic enthusiasm has surged to its highest level in decades,” Coyle said. “James Talarico is building the campaign to win, and Texans will send him to the U.S. Senate in November.”In his own statement, Talarico said it doesn’t really matter if Paxton or Cornyn wins the Republican primary, because he’s going up against the same thing in both of their cases.“We already know who we’re running against: the billionaire mega-donors and their corrupt political system,” he said.“For decades, John Cornyn and Ken Paxton have embodied a broken politics that enriches wealthy donors while costs skyrocket for the rest of us,” Talarico said. “Our movement to take back Texas for working people rises above party politics — because the biggest fight in this country is not left versus right, it’s top versus bottom.”Cornyn has served in the Senate since 2002. After the first round of primary voting in this race, when neither candidate received 50% of the vote, Senate Majority Leader John Thune (R-S.D.) openly pleaded with Trump to back Cornyn.“If the president can weigh in, it would be enormously helpful,” Thune told reporters in March, after Cornyn narrowly edged Paxton in the first round of voting.Asked later Tuesday how disappointed he was by Trump endorsing Paxton, the Senate Republican leader said he’s standing by Cornyn.“None of us control what the president does,” Thune told reporters on Capitol Hill. “He made his decision about that. That doesn’t change the way I feel.... I continue to be supportive of Sen. Cornyn and his reelection.”He said he learned of Trump’s endorsement “the way everybody else did,” meaning he saw it on social media versus hearing from the president directly.Trump has teased his endorsement in this race for months. He’s also said that whoever doesn’t get his endorsement should bow out.