That, combined with Barr's sweeping view of executive power, prompted Leahy to vote no on Barr's nomination.
The nomination now heads to the Senate floor, where Republicans have a 53-47 majority over Democrats and Democratic-caucusing independents.
In a statement Thursday afternoon, Sen.
"We need a new attorney general", Graham said on Thursday. Barr has said he will be as transparent as possible under Justice Department regulations, but many Democrats are skeptical. "I was very impressed with our conversation", Sullivan's statement said in part.
Chuck Schumer, the senior Democrat in the Senate, said he would oppose Barr's confirmation in the final vote.
In his hearing, Barr pledged to release "as much as I can" of Mueller's findings to the public, to provide Mueller with the resources and time to finish the job, to not terminate Mueller without good cause and to notify Congress if he denied a major request during the investigation.
Opponents have also cited a memo Barr wrote to the Justice Department before his nomination in which he criticized Mueller's investigation for the way it was presumably looking into whether Trump had obstructed justice.
A practicing Catholic and a member of the Knights of Columbus, Barr said in his confirmation hearings that he did not believe his faith would hinder his ability to serve as an effective attorney general.
Sen. Lindsey O. Graham (R-S.C.), the committee's chair, said that Barr had to be talked into returning to the Justice Department and that he trusted him to be "fair to the public and true to the law". Amy Klobuchar, D-Minn., said.
Some Democrats have also expressed concern that Barr won't be a check on the president who appointed him.
Whitaker said late last month the Mueller-led investigation is "close to being completed", although there has been no confirmation of this from the special counsel's office.
But the evidence so far shows that a broad range of Trump associates had Russia-related contacts during the 2016 presidential campaign and transition period, and several lied about the communication. Trump calls the probe a "witch hunt".