WASHINGTON — When Senator Steve Daines, the leader of the Senate Republican campaign arm, quietly informed Senator Mitch McConnell, the minority leader, that he intended to endorse former President Donald J. Trump, Mr. McConnell was fine with the idea.
Mr. McConnell, the Kentucky Republican, is not on speaking terms with the former president, having abruptly turned against him after the Jan. 6, 2021, attack on the Capitol. Mr. Trump has publicly savaged the senator and repeatedly demeaned his wife with racist statements.
But the minority leader, according to a person familiar with his thinking, believed that somebody in the Senate G.O.P. leadership ranks should have a working relationship with the party’s leading presidential contender — and it might as well be the man charged with winning back the Senate majority.
Mr. Daines’s endorsement of Mr. Trump this week — and Mr. McConnell’s private blessing of it — highlighted how top Senate Republicans have quietly decided to join forces with their party’s leading presidential candidate, putting aside the toxic relationship that some of them have with him to focus on what they hope will be a mutually advantageous political union.
Mr. Daines of Montana, the chairman of the National Republican Senatorial Committee, is the first and so far only member of the Senate G.O.P. leadership team to endorse Mr. Trump. Mr. McConnell, who enabled Mr. Trump and his agenda during much of his presidency before the Capitol riot, has not spoken to the former president since December 2020. His No. 2, Senator John Thune of South Dakota, also has been mercilessly attacked by Mr. Trump.
Mr. Thune portrayed Mr. Daines’s embrace of the former president as the cost of doing business — what’s necessary to win.
“He’s got a tough job to do,” Mr. Thune told reporters at the Capitol. “He’s got a lot of races around the country that we need to win. And I think he wants as many allies as possible.”
Asked about the fact that Mr. Daines has endorsed someone who has attacked both him and Mr. McConnell, the senator was temporarily at a loss for words.
“Well,” Mr. Thune said with a pause, “what can I tell you?”
Many Senate Republicans, in contrast to their counterparts in the House, view Mr. Trump as a political anchor who cost them the majority in 2020 with baseless claims of voter fraud in Georgia that damaged their runoff chances. Many believe Mr. Trump cost them again in 2022 by endorsing Senate contenders who struggled in the general election. Mr. McConnell has attributed his party’s inability to win the Senate to “candidate quality” problems spurred by Mr. Trump’s primary endorsements.
Steven Cheung, a spokesman for Mr. Trump, said that there was “tremendous support nationally and statewide” for the former president, when asked about Senate Republican leaders’ reluctant acceptance of Mr. Daines’s endorsement.
“By contrast, DeSantis has embarrassingly tiny support,” Mr. Cheung said.
Some Republicans are determined to steer clear of Mr. Trump. Senator Mitt Romney of Utah, a vocal critic of Mr. Trump’s who voted to convict the former president in both of his impeachment trials, insisted that Mr. Daines’s backing for Mr. Trump should not be regarded as an embrace of the former president by the Senate G.O.P.
“Montana is a big Trump-supporting state,” Mr. Romney said on Wednesday. “I don’t think he did that as the leader of the Republican team. Mitch McConnell is our leader, and I doubt he’ll endorse anybody.”
A spokesman for Mr. Daines declined to comment on Mr. Romney’s characterization of the endorsement.
Some wondered whether Mr. Daines was deliberately defying Mr. McConnell like the last chairman of the party campaign arm, Senator Rick Scott of Florida, did during last year’s midterm elections.
“I was surprised,” Senator Joni Ernst of Iowa, another member of the party leadership, said this week when asked what she thought of the Daines endorsement. “But all of the senators have the opportunity to endorse who they want to endorse.”
In fact, Mr. Daines and Mr. McConnell are on the same page.
Mr. Daines gave Mr. McConnell a heads up that he would be endorsing Mr. Trump ahead of a Monday night appearance on the podcast of Donald Trump Jr., the former president’s eldest son, according to the person familiar with his thinking.
Mr. McConnell views Montana, West Virginia and Ohio — which Mr. Trump won by big margins — as among the most important Senate battlegrounds in 2024, and it will fall to Mr. Daines to keep the former president on friendly terms with the party’s favored candidates, especially in the states where he remains wildly popular.
While the rest of Mr. McConnell’s team keeps their distance from the former president, Mr. Daines speaks frequently with Mr. Trump, including as recently as Wednesday night, said a person with direct knowledge of the call who was not authorized to discuss it publicly.
So even after Mr. Trump has denigrated Mr. McConnell’s wife, Elaine Chao, the Senate minority leader has engaged in a familiar game with the former president, with whom he worked closely to cut taxes and stack the federal judiciary with ardent conservatives.
Mr. McConnell has said as little as possible about the former president since cutting off all contact with him. He has ignored Mr. Trump’s attacks against him and his wife, and he has refused to follow the approach of former Representative Liz Cheney, Republican of Wyoming, who has said she plans to do whatever she can to stop Mr. Trump from becoming president again.
Instead, Mr. McConnell has said he is focused on winning back the Senate, and in service of that goal he is already making accommodations for the former president. He has said he will support Mr. Trump if he wins the 2024 Republican nomination.
Like many of his colleagues, Senator John Cornyn of Texas, a former chairman of the Republican campaign arm himself, is staying out of Mr. Trump’s way. He said he did not plan to endorse in the primary, but “will support the nominee” in the general election.
Mr. Daines, he said, was “entitled to some latitude given the complexity of the political environment that we’re entering into.”
Republicans’ goal, Mr. Cornyn added, was to win back the majority.
“And I don’t really care what the tactics are,” he said.
