Republicans are worried that Trump's latest endorsement will cost them control of the Senate, according to a new report. A Republican familiar with Texas politics told NOTUS that Trump's endorsement of the state's Attorney General Ken Paxton could cost the GOP its Senate majority in the upcoming midterms, according to a report. Trump endorsed Paxton on Tuesday instead of Sen. John Cornyn ahead of the Texas runoff for the Republican Senate nomination. "As late as Monday afternoon, Senate leaders believed Trump was going to stay out of the race," a source told NOTUS. "Especially with the runoff just a week away."Sen. Lindsey Graham (R-SC) said on Tuesday it would be harder to win the Senate seat with Paxton as the nominee, according to NOTUS. "I think Paxton can win, yeah, but I think it'd be three times more expensive," Graham said. Sen. Lisa Murkowski (R-AK) agreed, telling reporters, "We've got to raise a lot more money now," and that the endorsement "complicates" the GOP's effort to keep its Senate majority. "The fact that the president would choose to endorse not Sen. Cornyn, but a candidate who probably is going to struggle mightily in the general, is a problem," Murkowski added, according to NOTUS.Senate Majority Leader John Thune (R-SD) had been trying "to sway Trump toward endorsing Cornyn or, at the very least, staying out of the race," an aide told NOTUS. Trump told Thune in a phone call on Monday that "he was planning on endorsing Paxton but stopped short of saying it outright," a senior Republican aide said to NOTUS. "Thune left the conversation with little clarity about what Trump would do."