Sen. Amy Klobuchar (D-Minn.) said that Barr, as attorney general, would have the authority to change policies that now might prohibit him from revealing information about Mueller's work and that his nomination must be considered in the context of the historic moment in which the Justice Department finds itself.
The GOP head of the Senate Intelligence Committee says after two years of investigation, the panel still has not found evidence of collusion between the Trump campaign and Russian Federation.
Barr pledged at his confirmation hearing to keep politics out of Justice Department decisions and said he would refuse an instruction from the president to fire Mueller absent good cause to do so.
Chuck Grassley, an Iowa Republican, and Richard Blumenthal, Connecticut Democrat, introduced legislation requiring a special counsel to submit a report to Congress.
Barr, though, has extensive experience in law enforcement, even beyond holding the post as attorney general under the Bush Sr. administration.
The vote to limit debate on the lands bill is scheduled for Monday evening, meaning Barr's final confirmation should come no later than Thursday.
Barr, though, will be inheriting the Justice Department at one of the most politically charged periods in its history, as special counsel Robert S. Mueller III's investigation seems to be nearing its end.
"I don't believe Mr. Mueller would be involved in a witch hunt", Barr said at his hearing.
Chairman Lindsey Graham, R-S.C., said Barr told him that with respect to the special counsel's eventual findings, Barr would "not allow executive privilege as a reason to cover up wrongdoing".
He said Barr did not make such a commitment. Durbin said he would vote no. "In essence, Mr. Barr is asking the American people to trust him to do the right thing", Sen.
"I hope I'm wrong". Chris Coons, D-Del., said in a written statement ahead of the vote.
Sen. Dianne Feinstein of California, the committee's top Democrat, said that Barr did not commit to providing Mueller's report to Congress, only follow department rules and regulations on what should be public.
"This is particularly concerning, as nothing in existing law or regulations prevents the attorney general from sharing the report", Feinstein said Thursday.
But Durbin said Barr has "telegraphed his pitch" by writing an unsolicited memo to Justice Department and Trump lawyers previous year about parts of the special counsel probe. While Barr has vowed to be as transparent as he can be, Democratic lawmakers have said that is not adequate.
The committee also advanced dozens of nominations for federal appeals courts and district courts, many on a 12-10, party-line vote.