Rep. Adam B. Schiff (D-Burbank) now finds himself as the face of Democrats’ impeachment inquiry, leading the first House hearing into new allegations that President Trump withheld aid to Ukraine while pressuring that country’s president to investigate former U.S. Vice President Joe Biden.

It’s by no means Schiff’s first turn at such a role. He was the ranking Democrat on the House Intelligence Committee when it first began looking into allegations that the Trump campaign colluded with Russia in the 2016 election. By the time Schiff became committee chairman this year — after Democrats seized the House — the investigation had been largely taken over by special counsel Robert S. Mueller III. The Intelligence Committee hearings that followed the release of the Mueller report provided few fireworks and little new information.

House Democrats’ move this week to formally open an impeachment inquiry puts Schiff and his committee at the center of an entirely new and uncharted investigation into Trump.

This time there is no special counsel to rely on, and the Justice Department has already said it won’t investigate the claims. That creates an added sense of obligation to investigate thoroughly, Schiff told The Times in an interview. “That leaves us, and so, yes, a heavy responsibility comes with that.”

Other committees such as House Foreign Affairs will investigate aspects of a whistleblower’s complaint and other details that have emerged, and the House Judiciary Committee will make the final call on what articles of impeachment to present to the House. But the Intelligence Committee is expected to have jurisdiction over much of the actual investigation.

Schiff, an ally of Speaker Nancy Pelosi (D-San Francisco), wasted no time at Thursday’s hearing, asserting his commitment to pursuing the allegations. His opening statement mixed lofty quotations about constitutional obligations and biting comparisons between Trump and mafia bosses. His questioning of acting Director of National Intelligence Joseph Maguire was respectful but firm.

He inserted himself occasionally throughout the hearing, following up on other members’ questions and often extracting the most newsworthy moments from Maguire in what was a hearing largely focused on procedural issues.

Rep. Devin Nunes (R-Tulare), the ranking Republican, attacked Democrats for politicizing the whistleblower’s complaint about Trump, saying, “the Intelligence Committee is not an appropriate place to try articles of impeachment.”

But under Schiff’s stewardship, the hearing overall was far less combative and chaotic than the Judiciary Committee’s examination this month of Trump’s former campaign manager Corey Lewandowski. That hearing devolved into so much shouting and name-calling it raised concerns among some about Democrats’ ability to effectively lead an impeachment inquiry.

Schiff said he’s hoping to keep the investigation on track. “I would hope that it won’t be a circus. And you know, today’s hearing was contested, but it was very civil. And I think that’s the way it should be,” Schiff said. “I don’t know how much reason there is to think that the GOP members would support an impeachment effort no matter how justified.”

Pelosi stressed Thursday that the Intelligence Committee is taking the lead of the inquiry because it has jurisdiction over the complaint, downplaying rumors that Judiciary Committee Chairman Jerrold Nadler (D-N.Y.) is being sidelined over his handling of the Lewandowski hearing. “It is an intelligence matter and it is focused in the Intelligence Committee,” she told reporters.

But Ross Baker, political science professor at Rutgers University, said it is no accident Pelosi is entrusting Schiff with the job.

“Pelosi knows her personnel. Adam Schiff, of the six committee chairs who will have a slice of this impeachment examination, is probably closest to the top of his game,” Baker said. “Their second act has to be a comeback from the Mueller hearing, which was not a success for them. They want to hand the ball off to somebody who’s going to be a strong chairman.”

After the hearing, Schiff laid out an exhaustive schedule, saying the committee plans to work through the upcoming two-week recess. Among other things, he wants to hear the whistleblower’s testimony and speak to other administration officials who may have been aware of the president’s actions and an alleged attempt to cover them up.

“We have a lot of work to do, I think, before we can reach [a conclusion], and we don’t have an extended period of time to do it,” Schiff said.

He named Trump’s personal attorney Rudolph W. Giuliani and Atty. Gen. William Barr as among those whose involvement will be reviewed. Schiff also said he planned to investigate whether there are any other presidential conversations, similar to the July 25 call with the Ukrainian leader, in which the official accounts were allegedly moved to a special classified server to hide them.

“This may not be the only communication of a potentially corrupt character that was shielded by this classified information computer system abused for that purpose,” Schiff said.

Several House Democrats said this week that Schiff is the right person to lead the Ukraine investigation because of his knowledge of the topic and his passion.

“He’s extremely smart. He is a sophisticated prosecutor,” Rep. Karen Bass (D-Los Angeles) said. “He’s the perfect one to lead that part of it.”

With his high-profile role in confronting the Trump administration, Schiff has become a fixture of cable news. That’s dramatically raised his political profile, but also opened him up to a flood of criticism from Republicans, who accuse him of partisan showmanship.

They demanded Schiff step down as chairman of the committee when the Mueller report didn’t live up to Schiff’s assertions that it would include clear evidence that the Trump campaign colluded with the Russian government to influence the outcome of the 2016 election.

Democrats similarly demanded Nunes step down when he was chairman, accusing him of working with the White House to divert attention from the investigation.

The lingering tension was immediately clear Thursday as Republicans lambasted Schiff for how he paraphrased — in his opening remarks — Trump’s conversation with the Ukrainian leader, replacing the men’s quotes cited in the White House account of the call with his own, far blunter and more sinister version of the conversation. Schiff defended his recharacterization, saying it was “part in parody.”

Rep. Peter T. King (R-N.Y.), who has praised Schiff in the past, said that Schiff has become more partisan since the Mueller report has been released and that it reflects poorly on the committee.

“You’re the chairman of an important committee, and you’re on national television saying the president is a mafia leader, a gangster and all this kind of stuff. It goes beyond what is acceptable,” King said.

King blamed Schiff’s political aspirations for the change, saying his demeanor changed in 2017 amid rumors that California Sen. Dianne Feinstein might not run for reelection. Schiff’s role as chairman has helped make him one of the top fundraisers in the Democratic Party. His interest in running for higher office is widely known.

Among those least happy with Schiff’s return to the impeachment fight? Trump.

The president watched part of Thursday’s hearing while on Air Force One, returning from the U.N. General Assembly. A clearly irritated Trump complained that now he would have to “put up with Adam Schiff — on an absolutely perfect phone call.”