WASHINGTON — The ongoing investigation into Russia’s interference in the 2016 election and possible collusion by associates of President Trump’s campaign took a dramatic turn on Thursday. For months, the focus has been on what happened last year and outside of government. Now for the first time, it has moved to inside the White House and specifically to questions about the president’s personal conduct in office.

The testimony by former FBI director James Comey before the Senate intelligence committee added that potentially explosive element to an investigation that is now in the hands of special counsel Robert Mueller. Allies and adversaries of the president will interpret Comey’s accounting of events in different ways, but there is no question that his appearance reshaped what already has been a debilitating problem for the administration.

It has been many years since a witness appeared on Capitol Hill and put a president in such potential jeopardy. Thursday’s session provided no new information about what the Russians did and certainly not about what Trump associates may have done. Comey saved whatever he might want to say about that for a closed session Thursday afternoon. Instead, the morning was a riveting portrayal of his interactions with the president in what amounted to a possible, though not proven, case of obstruction of justice.

For nearly three hours, the fired former director took questions from senators of both parties. He was direct and crisp in his answers, generally careful to avoid over interpretation of the facts as he recalled them. He was business-like throughout, truly animated only when he talked about the threat of Russian interference to this country and its democracy. “They’re coming after America,” he said. Overall, however, the effect of his appearance was to put the president on the defensive in ways that will demand a sworn and substantive rebuttal in some forum at some point.

In Comey’s recounting of a series of meetings and phone calls, the president was continually frustrated by the degree to which the Russia investigation was harming his efforts to move ahead with his legislative and executive agenda. He wanted the cloud lifted with some kind of statement that would show he was not the focus of any investigation for collusion. Now, with Thursday’s testimony, that cloud will persist until Mueller has concluded his work.

Comey’s testimony was damning to the president. He said he did not trust the president, concluding after a Jan. 6 meeting at Trump Tower that he needed to take detailed and contemporaneous notes of his conversations with Trump because he feared the president would lie about their interactions. He took a statement by the president at a one-on-one meeting on Feb. 14 that he hoped Comey could let go of the investigation into fired national security adviser Michael Flynn as a directive, not a wish. He saw to it that the memo about those comments was leaked publicly after his firing in the hope that it would lead to the appointment of a special counsel – as it did.

But his testimony was not definitive. Though they continued to talk, he said Trump asked him only once to let go of the Flynn investigation and that came the day after the president had forced his national security adviser to resign. No one else from the White House or the administration ever asked him to do so. At no time did Trump ask or suggest that the Russia investigation be shut down. He never cried foul directly to the president, despite his claims that he felt the president’s actions were, at a minimum, highly inappropriate. He never threatened to resign or seemingly thought about it.

To punctuate how personal and threatening Comey’s testimony was, Marc Kasowitz, the president’s personal lawyer, offered a public and point-by-point rebuttal on Thursday afternoon. The president, he said, never asked Comey to “let go” of the Flynn investigation. He stated, as had Comey, that Trump had said if one of his associates had done something wrong, it would be good to find out. He denied that Trump had told Comey at a one-on-one dinner on Jan. 27, “I need loyalty. I expect loyalty.” He emphasized what Comey had said, which is that Trump was not under investigation for colluding with the Russians.

Comey’s prepared testimony was released Wednesday. It was for the most part a just-the-facts description of events, so precise that Sen. James Risch, R-Idaho, praised it effusively as a skilled piece of legal writing. “This is as good as it gets,” he said. The written testimony was almost cinematic in the way the narrative unfolded, adding dramatic elements for a Washington thriller that has gripped the capital and the country for months and that has no foreseeable ending. The written testimony set up Comey’s public appearance as the latest episode in the reality show that has been the Trump candidacy and presidency.

The members of the Senate intelligence committee approached their duties responsibly and with little flair. The release of the testimony had given them all time to prepare their questions, which were much more to the point than is often the case at such hearings. There was no grandstanding; there were no windy speeches. With the time for questioning tightly limited, and with just one round for each member of the committee, there was little straying into extraneous issues.

To the degree there was, which was when Comey was asked about the FBI’s investigation into Hillary Clinton’s use of a private email server as secretary of state, the former director provided new and damning revelations about former attorney general Loretta Lynch. He said her tarmac meeting with former president Bill Clinton had prompted him to offer his findings publicly and he said she had urged him to call what the FBI was doing a “matter” rather than an “investigation.”

Republicans picked at Comey’s conduct and drew concessions. He conceded that he had been perhaps cowardly in not standing up to the president when, alone in the Oval Office, Trump had said he hoped Comey would let go of the Flynn investigation. Risch, in a series of questions, got Comey to acknowledge that he knew of no instance in which a wish or a hope of the kind he had described of Trump had led to prosecution for obstruction.

But Comey was firm in conveying his belief that the president was far out of line in his actions. Why else, he implied, would the president ask Attorney General Jeff Sessions to leave the Oval Office before making his comments about the Flynn investigation to Comey alone. The former director directly disputed Trump’s earlier claim that he had never asked for relief on the Flynn investigation. He accused the president and his associates of lying. “The administration chose to defame me and more importantly the FBI. . .Those were lies, plain and simple,” he said.

He repeated his belief that an FBI director, though appointed for a 10-year term to insulate him from political pressure, could be fired at any time for any reason. But he said the changing stories about his firing, specifically that the Russia investigation was the reason in Trump’s thinking, had raised his sense of concern and ultimately led him to put into the public domain the contents of the memo about the Oval Office meeting on Feb. 14. “I hoped it would result in the appointment of a special counsel.”

The buildup to Thursday’s testimony was predictably breathless, as is the case with so much these days. Most of what Comey had to say was already known before he was sworn in by committee chairman Sen. Richard Burr, R-N.C. Yet the moment and the setting took the story to a different level with a tighter focus than ever on the president.

If the president had hoped that in firing Comey he would lower the temperature on his administration, Thursday brought the opposite. The investigation is far from its conclusion and, as with so much about the investigation, the evidence is murky or disputable. But for the president and his White House, despite Kasowitz’s claim of vindication for his client, this was not a good day.