“I then heard President Trump ask, ‘So, he’s gonna do the investigation?’ Ambassador Sondland replied that ‘he’s gonna do it,’ adding that President Zelensky will do ‘anything you ask him to.’ ”

When Donald Trump addressed the White House press corps on Friday afternoon about the second day of the House impeachment hearings, his fury was clear. “The Republicans are given no due process whatsoever,” he said. “We’re not allowed to do anything. . . . In the history of our country there has never been a disgrace like what’s going on right now.” The question that set Trump off was about a tweet he sent on Friday morning, in which he attacked Marie Yovanovitch, the former U.S. Ambassador to Ukraine, who was testifying before the House Intelligence Committee. In the tweet, he wrote that everywhere Yovanovitch had been posted “turned bad.”

A number of Republican elected officials and commentators quickly distanced themselves from Trump’s tweet, which came as some G.O.P. members of the Intelligence Committee were praising Yovanovitch for her long record of public service and attempting to gloss over the reasons why Trump had pulled her out of Kyiv, in May. The ranking Republican on the committee, Devin Nunes of California, and his fellow Trump defender Jim Jordan, of Ohio, had evidently decided that there was nothing to be gained from trying to undermine Yovanovitch, who has served six Presidents during her thirty-three years in the U.S. diplomatic corps. How badly had Trump violated that strategy? Even Elise Stefanik, the young representative from upstate New York, who, during the two days of hearings this week, emerged as one of Trump’s principal protectors, couldn’t bring herself to defend his tweet.

“We’re not here to talk about tweets,” Stefanik said during a press briefing after the hearing. “We are here to talk about impeachment, and nothing in that room today, and nothing in that room earlier this week, nothing rises to the level of impeachable offenses.” Reporters persisted, asking whether Trump’s tweet amounted to intimidating a witness, as Adam Schiff, the chair of the Intelligence Committee, and other Democrats had claimed. “I happen to disagree with the tweet,” Stefanik said finally, before again claiming it had no bearing on the impeachment inquiry.

Worse was to come for Trump. Later on Friday, in a closed-door meeting, the impeachment committee heard testimony from David Holmes, a career Foreign Service officer who works at the U.S. Embassy in Kyiv. Holmes testified that, this past summer, he overheard a transatlantic phone call in which Trump asked Gordon Sondland, the U.S. Ambassador to the European Union, who is a central figure in the scandal, whether the Ukrainian President, Volodymyr Zelensky, was going to go ahead with investigations that Trump had demanded. This phone call took place on July 26th, just a day after Trump had spoken with Zelensky on a call and told him, “I would like you to do us a favor,” before bringing up the Democratic National Committee’s e-mail server and, later in the conversation, former Vice-President Joe Biden and his son Hunter.

According to the account that Holmes provided in his opening statement, which was leaked to the media on Friday night, Sondland called Trump on his cell phone from Kyiv, where he was having lunch on a restaurant terrace with Holmes, who is the political counsellor at the U.S. Embassy in Kyiv, and two other American diplomatic staffers. In more than five hours of public testimony on Wednesday, William Taylor, the top U.S. diplomat in Ukraine, told the Intelligence Committee that the call had taken place, and provided a brief outline of its content, drawing Trump further into the Ukraine mire. Holmes provided more detail, including some fragments of the conversation between Sondland and the President that he had overheard.

Sondland didn’t put the call on speakerphone, but Holmes could hear it through the earpiece, he said in his statement: “The President’s voice was very loud and recognizable, and Ambassador Sondland held the phone away from his ear for a period of time, presumably because of the loud volume.” Holmes went on, and said, “I heard Ambassador Sondland greet the President and explain he was calling from Kyiv. I heard President Trump then clarify that Ambassador Sondland was in Ukraine. Ambassador Sondland replied, yes, he was in Ukraine, and went on to state that President Zelenskyy ‘loves your ass.’ I then heard President Trump ask, ‘So, he’s gonna do the investigation?’ Ambassador Sondland replied that ‘he’s gonna do it,’ adding that President Zelensky will do ‘anything you ask him to.’ ”

It now seems highly likely that the Intelligence Committee will call Holmes to offer public testimony. As of Saturday morning, he wasn’t scheduled to testify next week, when several more witnesses are supposed to appear before the cameras, including Sondland, on Wednesday. That session, assuming it goes ahead, is shaping up as a pivotal moment of the impeachment inquiry. Although Sondland, a Seattle hotelier and major Trump donor, is widely viewed as a loyalist to the President, he expressed some dismay about the Ukraine caper during his closed-door testimony last month, noting that “it kept getting more insidious as [the] timeline went on.” And just last week, Sondland amended his initial testimony to say that he subsequently remembered telling one of Zelensky’s top aides, at the start of September, that “resumption of U.S. aid would likely not occur until Ukraine provided the public anti-corruption statement that we had been discussing for many weeks.” By confirming that he informed the Ukrainians about Trump’s quid pro quo, Sondland also confirmed the closed-door testimony of William Taylor.

Will Sondland confirm Holmes’s account of the July 26th call? In his opening statement, Holmes said that he didn’t take notes of the call, but also said, “I have a clear recollection that these statements were made. I believe that my colleagues who were sitting at the table also knew that Ambassador Sondland was speaking with the President.” Moreover, the assertion that Trump asked about an investigation and Sondland assured him it was going to take place isn’t the only damaging material in Holmes’s testimony.

He also recalls that, after the call between Trump and Sondland ended, Sondland noted that Trump appeared to be in a bad mood, as he often was early in the morning. “I then took the opportunity to ask Ambassador Sondland for his candid impression of the President’s views on Ukraine,” Holmes’s statement goes on. “In particular, I asked Ambassador Sondland if it was true that the President did not ‘give a s--t about Ukraine.’ Ambassador Sondland agreed that the President did not ‘give a s--t about Ukraine.’ I asked why not, and Ambassador Sondland stated that the President only cares about ‘big stuff.’ I noted that there was ‘big stuff’ going on in Ukraine, like a war with Russia, and Ambassador Sondland replied that he meant ‘big stuff’ that benefits the President, like the ‘Biden investigation’ that Mr. Giuliani was pushing. The conversation then moved onto other topics.”