"They paid for it", said Sen.
Trump then made the highly controversial decision to install Sessions' chief of staff, Matthew Whitaker, as acting attorney general.
To date, the committee has interviewed more than 200 witnesses and reviewed more than 300,000 pages of documents; it has held more than a dozen public hearings and released two interim reports, CBS News reported. Patrick J. Leahy (D-Vt.) said he was concerned Barr's previous testimony on the subject "could lay the groundwork for potentially no transparency at all".
During his confirmation hearing earlier this year, Barr, 68, assured senators of his independence and said that he would not be bullied by anyone into doing something he believes is wrong if he becomes the attorney general.
"This is not a time to mess around with the Constitution", she said. Chuck Grassley, an Iowa Republican, and Richard Blumenthal, Connecticut Democrat, introduced legislation requiring a special counsel to submit a report to Congress.
Barr said he takes seriously the department regulations that say Mueller's report should be confidential. He has served honorably and I expect he will be a steady hand at the Department of Justice. And he praised Barr emphatically. "We are already seeing unsafe threats to the rule of law".
Lawmakers have raised questions about a memo Barr wrote to Justice Department leaders questioning what he saw as the "fatally misconceived" theory of Trump obstructing justice that Mueller seemed to be exploring. Dan Sullivan, R-AK, said he met with Barr Thursday to discuss issues related to Alaska.
Barr was selected after former attorney general Jeff Sessions was pushed out in November 2018. But he said he could not understand the memo and would vote against Barr's nomination.
Democrats on the U.S. House of Representatives' Judiciary Committee on Thursday prepared a subpoena to compel Whitaker to testify on Friday, prompting him to say he will not appear unless the subpoena threat is lifted.
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.