In recent weeks, Mr. McCarthy has called House impeachment “a national nightmare,” “rigged” and a “last attempt to stop the Trump presidency.” He claimed the F.B.I. “broke into” Mr. Trump’s campaign in a “modern-day Watergate.” He suggested that former Vice President Joseph R. Biden Jr. should suspend campaigning while many of his top rivals for the Democratic presidential nomination, Senators Bernie Sanders of Vermont, Elizabeth Warren of Massachusetts and Amy Klobuchar of Minnesota, sit as captive jurors in the impeachment trial.

His delivery lacks the razor edge of his fellow House Republican leader Liz Cheney, who announced on Thursday that she would forgo a campaign for Wyoming’s open Senate seat to remain in the House, a veiled threat to challenge Mr. McCarthy for the speakership if Republicans regain the majority. He never attains the volume of Representative Jim Jordan of Ohio, who has challenged him for Republican leadership posts, or the umbrage of Representative Devin Nunes, a Republican from the California district next door.

“He’s a nice guy,” said Representative Thomas Massie, Republican of Kentucky, with a verbal shrug.

Five minutes later, Mr. Massie texted an additional thought: “I can say this about Kevin, he’s been far more helpful to the president than Paul Ryan would have ever been during this impeachment sham.”

For now, that may be his main job: making the president happy.

“Where is Kevin McCarthy, the great Kevin McCarthy?” Mr. Trump demanded last week at a China trade event at the White House. When it was clear the minority leader was in the House, preparing for the vote to send articles of impeachment to the Senate, the president added: “Kevin McCarthy, as you know, left for the hoax. Well, we have to do that; otherwise, it becomes a more serious hoax.”

It is no small thing to the president that Mr. McCarthy kept House Republicans unified in their opposition to Mr. Trump’s impeachment. House Republicans include “former prosecutors who probably don’t love the president, moderates who are retiring and thinking, ‘I’m going to vote to impeach the president because I want my grandchildren to talk to me again,’” said John Feehery, a Republican strategist. “That they didn’t is a significant victory for the president, and a significant victory for Kevin McCarthy.”