By Jordain Carney, The Hill–

The fate of special counsel Robert Mueller’s probe is looming large over a high-stakes hearing for President Trump’s attorney general nominee.

William Barr will be in the hot seat next week when he faces the Senate Judiciary Committee for a two-day grilling that is expected to focus on the fate of Mueller’s investigation into the 2016 election and potential collusion between the Trump campaign and Moscow.

Democrats were already anxious over Barr because of an unsolicited memo he drafted criticizing Mueller’s investigation. But those concerns have ballooned amid reports that Deputy Attorney General Rod Rosenstein, who appointed Mueller and has overseen the investigation, will be leaving the Justice Department.

Sen. Dick Durbin (D-Ill.), the No. 2 Senate Democrat and a member of the committee, predicted that the special counsel investigation will be “front and center” at the hearing.

“There’s so many questions to ask him [about] when he volunteered his own opinion about the authority of Bob Mueller-troublesome to me,” he said. “I’m sure he’ll deny any culpability and assure me he’ll be a straight arrow, but I come to it with a degree of skepticism.”

Senate Minority Charles Schumer (D-N.Y.) added during a floor speech that Rosenstein’s potential departure “only heightens the stakes” for Barr’s nomination.

Barr began making the rounds this week to meet with some members of the committee, including newly minted chairman Lindsey Graham (R-S.C.).

Graham and other GOP senators have dismissed concerns about whether Barr will interfere with the investigation. Speaking to reporters after his meeting with Barr, Graham characterized the two men as “best friends,” noting that their wives attended bible study together and that Mueller had gone to Barr’s daughters’ weddings.

During private meetings with senators, Barr tried to defuse tensions over his views on Mueller. If he is confirmed as attorney general he would have oversight of the investigation.

Sen. Chris Coons (D-Del.), a member of the panel, said some of Barr’s answers during their 40-minute meeting about the Mueller investigation were “very encouraging.”

“That he knows and respects Robert Mueller and served alongside him. That he intends to allow that investigation to conclude, to reach its natural conclusion, unhindered. That he sees it as critical to the rule of law and the legitimacy of the Department of Justice … for Mueller’s investigation to conclude,” Coons said recalling what Barr told him during their meeting.

Sen. Dianne Feinstein (D-Calif.) added that Barr offered assurances to “some extent” during the meeting, describing Trump’s pick as “affable” and that the closed-door chat allowed her to “break the ice.”

Democrats are expected to grill Barr during the closely watched hearing about a controversial memo he sent to the Trump administration. They are also expected to seek public reassurances on Mueller.

“I don’t take to the bank anything unless it’s in public setting and everybody can hear and it’s on the record,” Feinstein added. “The question in my mind is will he leave Mueller alone – that means no interference, no budgetary control.”

Barr’s nomination came under fire after The Wall Street Journal reported last month that Barr wrote in an unsolicited memo that the Mueller probe is based on a “fatally misconceived” theory and would do “lasting damage” to the presidency.

Schumer immediately called on Trump to drop Barr, who had not been formally nominated at the time, and pick another attorney general candidate.

“The Senate, starting with the Judiciary Committee, should subject Mr. Barr’s views to the strictest of scrutiny … and I still believe, after the revelations about Mr. Barr’s unsolicited memo, President Trump ought to withdraw this nomination,” Schumer reiterated from the Senate floor this week.

Mueller has been a long-running target for Trump, who has insisted that his campaign did not collude with Russia and decried the investigation as a “witch hunt.” His legal team has also indicated they will try to use executive privilege to prevent swaths of Mueller’s final report from being released to the public.

While it has mostly pressed on behind the scenes for 19 months, Mueller’s probe into Russian interference and links between the Trump campaign and Moscow has yielded some bombshell developments.

Revelations this week in the case of former Trump campaign chairman Paul Manafort have triggered new questions about whether the campaign coordinated with Moscow.

Manafort’s defense attorneys inadvertently revealed in a court filing that Mueller accused Manafort of sharing polling data with a Russian associate suspected of ties to Kremlin intelligence during the campaign. Trump on Thursday denied knowledge of Manafort sharing the polling data.

Barr, if confirmed, would succeed Jeff Sessions, whose tenure as attorney general was in constant turmoil with Trump because of his decision to recuse himself from matters on Russia.

Democrats are already pushing for Barr to recuse himself from the Russian probe because of his memo criticizing Mueller. Every Democrat on the Judiciary Committee sent a letter to the Justice Department on Friday questioning if the agency had the ability to “assess and address potential conflicts” with Barr.

“Mr. Barr’s record, including statements and opinions that he has expressed regarding Special Counsel Mueller’s investigation, will be explored by Congress in the course of his confirmation, and will also warrant consideration by the Department’s career ethics officials if he is confirmed,” they wrote.

Republicans have argued that there is a distinction between what Barr wrote as a private citizen and how he would act as attorney general.

“He wrote that as a private citizen,” Grassley told CNN. “What you do as a private citizen is one thing. What you do as a public citizen is another.”

Barr has a decades-long history in Washington, D.C. that Republicans have seized on as they’ve tried to play up previous Democratic support for him. He won unanimous approval by the Judiciary Committee in 1991. Then-Sen. Joe Biden (D-Del.) praised him, according to the L.A. Times, as “a throwback to the days when we actually had attorneys general who would talk to you.”

Coons, who now holds Biden’s Senate seat, acknowledged that Barr’s experience in the Justice Department and as a lawyer is “encouraging,” but stressed that he believed the country is not “in normal times.”

“He didn’t serve in a period like this one where the very rule of law itself is at risk,” Coon said, “where there is a growing body of evidence that might suggest that the president and his senior campaign team may have engaged in either obstruction of justice or collusion.”