WASHINGTON — Senator Mitch McConnell’s colleagues may not have deep personal affection for their often distant and inscrutable leader, but there is considerable appreciation for how he has spared them from difficult votes while maintaining a laserlike focus on keeping the Senate majority.

His approach on Saturday at the conclusion of former President Donald J. Trump’s impeachment trial seemed aimed at doing just that. After voting to acquit Mr. Trump of inciting the Jan. 6 riot that invaded the Senate chamber, Mr. McConnell, Republican of Kentucky, began a fiery tirade, declaring him “practically and morally responsible” for the assault. In essence, Mr. McConnell said he found Mr. Trump guilty but not subject to impeachment as a private citizen.

The strategy appeared twofold: Don’t stoke a full-on revolt by Trump supporters the party needs by voting to convict, but demonstrate to anti-Trump Republicans — particularly big donors — that he recognized Mr. Trump’s failings and is beginning to steer the party in another direction.

But it did not exactly produce the desired result. Instead, it has drawn Mr. McConnell into a vicious feud with the former president, who lashed out at him on Tuesday as a “dour, sullen and unsmiling political hack,” and given new cause for Republican division that could spill into the midterm elections. And it has left some Republicans bewildered over Mr. McConnell’s strategy and others taking a harder line, saying the leader whose focus was always the next election had hurt the party’s 2022 prospects.

The miscalculation has left Mr. McConnell in an unusual place — on the defensive, with Mr. Trump pressing for his ouster, and no easy way to extricate himself from the political bind.

“McConnell has many talents, there is no doubt about it, but if he is setting this thing up as a way to expunge Trump from the Republican Party, that is a failing proposition,” Senator Ron Johnson, Republican of Wisconsin, said in an interview on Wednesday.

Mr. Johnson, who is weighing running for re-election next year in a highly competitive battleground state, said support for Mr. McConnell was already emerging as a negative factor among Trump-backing Republican primary voters he speaks with back home. He said the minority leader risked becoming a full-blown pariah for Senate candidates if he did not move quickly toward unifying the party.

Senator Lindsey Graham of South Carolina, in an interview Tuesday night with Sean Hannity on Fox News, said the fact that Mr. Trump and Mr. McConnell were “now at each other’s throats” was imperiling the political outlook for Republicans.

“I’m more worried about 2022 than I’ve ever been,” Mr. Graham said. “I don’t want to eat our own. President Trump is the most consequential Republican in the party. If Mitch McConnell doesn’t understand that, he’s missing a lot.”

Mr. McConnell needs to be returned to his top role after the 2022 elections to become the longest-serving Senate leader in history in 2023, a goal the legacy-minded Kentuckian would no doubt like to achieve. And there is no imminent threat to his leadership position, though one senator said privately that a challenge could have been incited had Mr. McConnell split with the 42 other Republican senators who voted to acquit Mr. Trump.

Mr. McConnell has been conspicuously silent since the attack by Mr. Trump. He made no effort to walk back his Saturday speech or a subsequent op-ed in The Wall Street Journal, but, characteristically, he now also appears uninterested in further inflaming the fight by punching back at Mr. Trump. David Popp, a spokesman for Mr. McConnell, declined to comment on Wednesday.

His Republican allies quickly circled around him, speaking in the void of his silence.

Senator Shelley Moore Capito of West Virginia said that Mr. McConnell was on “very solid ground” and that she had come away from conversations with him convinced he was moving forward with eyes open, prepared for the “slings and arrows” that taking on a vindictive former president would attract.

“He’s not exactly a stream-of-consciousness communicator. He is very circumspect, very disciplined in his speech, and I think the speech he gave on the floor regarding former President Trump came right from his heart,” Ms. Capito said in an interview. She added, “His classic technique is to put it out there, say what he thinks and keep moving forward.”

Senator John Thune of South Dakota, his No. 2 whom Mr. Trump has already promised to target next year, said in a statement that Mr. McConnell had “my full support and confidence.”

Senator John Cornyn of Texas said Mr. McConnell had expressed his horror at what had occurred. “I think it genuinely offended him what happened in the Capitol that night,” Mr. Cornyn said. “Obviously, he spoke his mind.”

Mr. Trump spoke his mind as well. In his Tuesday broadside that attacked Mr. McConnell in sharply personal terms despite their close collaboration over the past four years, Mr. Trump urged his party to abandon the Kentucky Republican. He also threatened to initiate primaries against Republican Senate candidates he believed were not sufficiently supportive of his agenda.

That is a possibility that worries Senate Republicans. Most are confident about gaining the one seat needed to take back the Senate in the coming 2022 midterm elections — unless their candidates engage in messy primary races that end up producing hard-right candidates who cannot win in the general election, an outcome that harmed Republicans in the past. Those memories have stuck with Mr. McConnell, who has promised to intervene in primaries if he believes a candidate is endangering the party’s chance of winning a general election.

Mr. Johnson said Republicans cannot win without the ardent Trump supporters now alienated by Mr. McConnell’s denunciation of Mr. Trump. He lumped the Republican leader in with the Lincoln Project and other anti-Trump Republicans who tried to “purge” the party of Trumpism. “They are not perceiving reality,” he said.

“You are not going to be able to have them on your side if you are ripping the person they have a great deal of sympathy for in what he has done for this country and the personal toll President Trump has shouldered,” he said.

Mr. McConnell’s allies acknowledged that Mr. Trump still had a hold on the Republican base but one said that Republicans should still be able to come together in opposition to what they saw as a far-left progressive agenda pursued by President Biden and congressional Democrats.

“The unfortunate consequences of Democrats’ power was on full display in the opening days of the Biden administration when it effectively fired thousands of union workers, when it canceled the Keystone XL pipeline and froze oil and gas leases on federal lands,” said Antonia Ferrier, a former communications director to Mr. McConnell.

Despite the heat of the current moment, some Republicans say they expect Mr. McConnell to weather the current hostile environment as he has in the past, aided by the passage of time and developments that diminish Mr. Trump’s hold on the party. They say he has survived challenges from the right in the past and stamped out primary challenges that threatened his preferred candidate.

“Two years from now,” Mr. Cornyn said, “things could look completely different.”