Senators debated Barr's candidacy for several hours, focusing on his potential role in supervising special counsel Robert Mueller in the Russian Federation investigation.
Addressing the memo, Barr said it was "very common" for him and other former senior officials to offer their opinions on DOJ matters they believed to be legally improper. While Barr has vowed to be as transparent as he can be, Democratic lawmakers have said that is not adequate. Dianne Feinstein, D-California, called a memo in which Barr was critical of Mueller's probe "disqualifying", saying she's anxious that he has not committed to releasing Mueller's report to Congress.
Trump then made the highly controversial decision to install Sessions' chief of staff, Matthew Whitaker, as acting attorney general.
President Trump's pick to be the next attorney general is one step closer to be confirmed. "And I think we have to get to the bottom of it", Barr said. "I hope if he's the next attorney general, and he's likely to be, that what I saw in his family, what I saw in his resume, what I've seen in his commitment to the issue of justice, will come through clearly", Sen.More news: Kings send Iman Shumpert to Rockets in 3-team trade with Cavs
A year ago he sent an unsolicited legal opinion to the Justice Department and White House arguing that Mueller had no grounds to investigate Trump for obstruction of justice based on the firing of Federal Bureau of Investigation director James Comey in May 2017.
"I appreciate what Mr. Whitaker has done, but I think the time has come for new leadership at the department", Sen.
But he said he could not understand the memo and would vote against Barr's nomination. That, combined with Barr's sweeping view of executive power, prompted Leahy to vote no on Barr's nomination.
But Durbin said Barr has "telegraphed his pitch" by writing an unsolicited memo to Justice Department and Trump lawyers past year about parts of the special counsel probe.
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.