Republican quits Senate bid just days after announcement after failing to get Trump endorsement

Matt Rosendale dropped out once the former president endorsed his would-be primary opponent

Congressman Matt Rosendale, a Republican who launched his bid for the Senate less than a week ago, announced he is no longer running for the seat.

He issued a statement saying he dropped out because Donald Trump did not endorse him, according to Politico.

“As everyone knows, I have planned to run for the U.S. Senate and to win both the primary and the general election,” Mr Rosendale said in a statement. “However, the day I announced, President Trump then announced that he was endorsing a different candidate.”

Mr Trump tossed his support to Tim Sheehy, a former Navy SEAL and aerospace businessman. Mr Sheehy has also been endorsed by the National Republican Senatorial Committee.

Republicans in the state are trying to unseat Democratic Senator Jon Tester, and likely view Mr Rosendale's abrupt drop-out as a positive, saving the party the money and trouble of running a primary contest.

Mr Rosendale said he spoke with the chairs of the NRSC about his candidacy and ultimately agreed that "this is the best path forward for Republicans to regain the majority in the US Senate," NBC News reports.

“This race was already going to be tough, as I was fighting against [Senate GOP Leader] Mitch McConnell and the rest of the Republican establishment in Washington,” Mr Rosendale said. “But I felt like I could beat them, as the voters do not agree with them choosing who would be the next U.S. Senator from Montana.”

Mr Rosendale said that Mr Trump's endorsement of his would-be opponent and his lack of resources made the hill "too steep" for him to climb.

Senator Steve Daines, the state's Republican senator, said he appreciated Mr Rosendale's decision.

“I appreciate Matt’s many years of service to Montana,” Mr Daines said in a statement on Thursday night. “It will take all Republicans working together to defeat Jon Tester in November.”

Mr Sheehy also offered his appreciation to Mr Rosendale for leaving the primary.

Representative Matt Rosendale has dropped out of a Senate race less than a week after he announced his run (Getty Images)

“Matt, Montana is grateful for your service and for showing Washington, D.C. what it means to hold the line on reckless spending,” Mr Sheehy wrote. “I know working together we’ll win this race and defeat Jon Tester.”

State Democrats weren't buying the show of unity, pointing out that prior to his run, Mr Rosendale spent considerable time making the case that Mr Sheehy wasn't right to lead the state in the Senate.

“Rosendale spent months making the case that Tim Sheehy has no place representing Montana in the Senate and he was right,” Montana's Democratic Party executive director Sheila Hogan said. “Sheehy is an out-of-state tech millionaire completely out of touch with Montana’s way of life.”

It's unclear what Mr Rosendale will do next. He has until 11 March to decide if he will run for re-election in the House. However, if he does, he'll face a sizable field of primary opponents who were primed to take his empty seat.

Mr Rosendale said he will "prayerfully consider what is next" over the course of "the next few days," according to a report by Axios.