The misfire came as the White House scrambled to coordinate responses to Democrats who the day before had announced a formal impeachment inquiry. Democratic Party leaders have accused the president of betraying his oath of office in seeking Mr. Zelensky’s help in targeting former Vice President Joseph R. Biden Jr., a leading contender for the Democratic presidential nomination.

On Wednesday, the White House released a reconstructed transcript of the call between the two men and invited a dozen or so top Republican lawmakers, including Representatives Kevin McCarthy , Steve Scalise and Liz Cheney, to review the document in advance and pose questions, officials familiar with the meeting said. At one point, Mr. Trump dialed into the meeting from the United Nations.

“The House Democrats have been careening from impeachment theory to impeachment theory, they’ve careened from target to target,” Ms. Cheney said on Wednesday. She accused Ms. Pelosi of “trying to weaken the president, trying to weaken his hand as he’s dealing with crucial issues of national security.”

One of the few exceptions was Senator Mitt Romney, Republican of Utah, who pointedly did not suggest that Ms. Pelosi had gone too far: “She’s able to do what she feels is right. That’s up to her.”

And he expressed deep concern for what he had read.

“Clearly what we’ve seen in the transcript is deeply troubling,” Mr. Romney told reporters.

Later, at The Atlantic’s annual discussion festival, he explained why he thought his party was sticking to the talking points. “I think it’s very natural for people to look at circumstances and see them in the light that’s most amenable to their maintaining power,” he said, “and doing things to preserve that power.”

Maggie Haberman and Nicholas Fandos contributed reporting.