Updated at 5:17 p.m. ET
President Trump's choice to lead the Justice Department, William Barr, took questions from lawmakers Tuesday, with the central one being whether Barr will work to impede the Russia investigation.
Barr, who previously served as attorney general under President George H.W. Bush, appeared before the Senate Judiciary Committee for the first day of his confirmation hearing.
"[Barr] has shown his commitment to the Constitution time and time again. That's why he has been confirmed by the Senate three times," said former Sen. Orrin Hatch, R-Utah, who introduced Barr at the beginning of the hearing.
Almost every Democratic senator, and some Republicans, including Judiciary Chair Sen. Lindsey Graham, R-S.C., focused their questions for Barr on special counsel Robert Mueller's Russia investigation.
"Now perhaps more than ever before," said ranking member Sen. Dianne Feinstein, D-Calif., "the country needs someone who will uphold the rule of law, defend the independence of the Justice Department and truly understand that their job is to serve as the people's lawyer, not the president's lawyer."
Barr attempted to reassure those worried by his skepticism of Mueller's office by vowing to permit Mueller to complete his work investigating the Russian attack on the 2016 election.
Mueller is determining whether any Americans played any role, and The New York Times has reported that may include a direct look at Trump himself.
Speaking to reporters Monday, the president denied that he has been trying to conceal details about his discussions with Russian President Vladimir Putin after a pair of explosive press reports over the weekend.
"I never worked for Russia," Trump said. "It's a disgrace that you even asked that question because it's a whole big fat hoax. It's just a hoax."
On Tuesday, Barr said it was "very important" for the public and Congress to see the results of the Mueller investigation. A number of Democrats suggested that Trump may try to pressure or manipulate him, but Barr was adamant that that won't happen.
"I'm not going to do anything that I think is wrong and I'm not going to be bullied into doing anything that I think is wrong," Barr said. "By anyone – whether it's editorial boards or Congress or the president, I'm going to do what I think is right."
Barr said he does believe Russia attempted to interfere with the 2016 election, and he also said he agreed with former Attorney General Jeff Sessions' decision to recuse himself from overseeing the probe into that interference.
But Barr declined to say conclusively that he would recuse himself due to the criticism he has offered of the Mueller investigation, saying instead that he would consult ethics experts at the Justice Department but ultimately that decision was his to make.
He promised to provide Mueller the adequate resources and time to complete the probe and noted that he could only terminate Mueller for good cause under the Justice Department's regulations governing oversight of special counsels and their investigations.
"Frankly, it's unimaginable to me that Bob would ever do anything that gave rise to good cause," said Barr. "The overarching public interest is for the investigation to finish."
Barr and Mueller are longtime friends. Mueller attended the weddings of Barr's children and Barr said he expected to remain friends with Mueller past the end of the Russia imbroglio.
The confirmation hearing touched on a number of other topics, including immigration, recent bipartisan legislation overhauling aspects of the criminal justice system and battling illegal drugs. Barr said he would support a federal law banning the recreational use of marijuana, but said he would not use federal resources to crack down on states that allow the practice.
Barr also repeatedly voiced support for a wall or "barrier" at the United States' southern border.
Trump needs no Democratic Senate votes for his nominee to be confirmed, as Republicans hold a 53-47 advantage in the chamber, and Cabinet nominees require just a simple majority.
Based on the comments made by members of Congress on Tuesday, and in meetings with Barr ahead of the hearing, Barr appears to be on track to take the top job at the Justice Department.
Deputy Attorney General Rod Rosenstein, who has been supervising the Mueller investigation since Mueller's appointment as special counsel, is expected to leave his post at DOJ after Barr's confirmation so that Barr can select his own deputy.
The Senate Judiciary Committee will meet again Wednesday for the second day of the confirmation hearing, which will feature a number of legal experts and advocates.