At the same time, former colleagues and friends say the man who led the Justice Department once before -- under President George H.W. Bush -- is "not a lap dog for anyone.”
In prepared remarks to the Senate Judiciary Committee, made public Monday, Barr says, “I believe it is in the best interest of everyone – the President, Congress, and, most importantly, the American people – that this matter be resolved by allowing the Special Counsel to complete his work.
"The country needs a credible resolution of these issues. If confirmed, I will not permit partisan politics, personal interests, or any other improper consideration to interfere with this or any other investigation,” Barr's testimony reads.
“Second, I also believe it is very important that the public and Congress be informed of the results of the Special Counsel’s work. For that reason, my goal will be to provide as much transparency as I can consistent with the law. I can assure you that, where judgments are to be made by me, I will make those judgments based solely on the law and will let no personal, political, or other improper interests influence my decision.”
“I mean, clearly he’s a good lawyer, no question, but when it comes to this delicate political situation — the power of the presidency, whether this investigation is warranted — Bill Barr had better give us some ironclad, rock-bottom assurances in terms of his independence and his willingness to step back and let Mueller finish his job,” Democratic Sen. Dick Durbin told Chief Anchor George Stephanopoulos on ABC's "This Week."
Democrats want to know why Barr wrote the memo and who else might have seen or known about it.
“To some extent, he’s a known factor. I mean he’s been there before. So the key is the times change, views change and laws change so the question is, is he right for this time and can he really be independent of the White House,” Sen. Dianne Feinstein, a California Democrat, said after her exchange with Barr.
Democratic Sen. Chris Coons of Delaware told reporters after his meeting with that while he felt somewhat reassured, he continued to have concerns.
Coons said that, although Barr told him the Mueller investigation is “critical to the rule of law,” and that he would let Mueller finish, the current situation is unprecedented.
“We are not in normal times, it’s encouraging that the president nominated someone who served as Attorney General before but he didn’t serve in a period like this one, where the very rule of law itself is at risk and where there is a growing number of facts that suggest either he or his senior campaign team may have engaged in obstruction of justice or collusion,” Coons stressed.
Coons said he intends to ask Barr the same questions in his public hearing to let him speak for himself.
But those who have worked with Barr have nothing but praise for the former attorney general under Bush.
Back then, after leaving the Justice Department, he tackled a new project: criminal justice reform and reforming parole in the Commonwealth of Virginia.
Former Virginia governor and U.S. senator, George Allen, who nominated Barr to chair the project called "Truth in Sentencing," which according to Allen lowered violent crime and recidivism rates, told ABC News that in order to get legislation through the Virginia State House, he had to persuade Democrats and Republicans that it was necessary - a skill Allen thinks will translate well in a second stint as attorney general.
“He is steady to the law," Allen told ABC News. His judgment will be "based on the law."
Barr respects institutions, the Constitution and the law, Allen said.
He predicted Barr will be unflappable in his confirmation hearing and display a "slightly dry sense of humor."
The commission that Barr chaired eventually led to legislation being passed and led to sentencing rates that decreased, Allen said.
George Terwilliger, who succeeded Barr as Deputy Attorney General and is now a partner at McGuire Woods, said that Barr is a "lawyer's lawyer."
"Bill has a lifetime of achievement, making good judgments in challenging circumstances," Terwilliger told ABC News.
Richard Cullen, who became friends with Barr when he was U.S. Attorney for the Eastern District of Virginia and Barr was attorney general, told ABC News that he doesn't think there is anyone more prepared for the job.
"Not only has he been there once and done it, add to that 20 plus years of business experience in cutting edge issues," he said, citing Barr's work as counsel for Verizon when the company switched from a landline company to an entertainment conglomerate.
He also noted that, personally, everyone loves being around him and praised his sense of humor and intellect.
Jay Timmons, Allen's former chief of staff and now National Association of Manufacturers President and CEO, also lauded the pick.
“President Trump could not have nominated a better individual than Bill Barr for Attorney General of the United States, and manufacturers are encouraged by this outstanding nomination,” Timmons said in a statement.
"Manufacturers are confident he will bring the same sterling commitment to the rule of law to the Justice Department that he has shown throughout his storied career, and we are equally confident the Senate will set aside partisanship as they consider the confirmation of this highly respected public servant,” Timmons continued.
Colleagues who spoke to ABC News all described him as steady and noted he doesn't need any on the job training.
"Because he is a superior lawyer, he is able to reach a solid judgment," Terwilliger said.