WASHINGTON (Reuters) - Newly installed U.S. Attorney General William Barr must walk a political and legal tightrope in deciding how much of Special Counsel Robert Mueller’s report on Russia’s role in the 2016 election to disclose, balancing competing demands from President Donald Trump and congressional Democrats, legal experts said.

FILE PHOTO: William Barr testifies at the start of his U.S. Senate Judiciary Committee confirmation hearing on his nomination to be attorney general of the United States on Capitol Hill in Washington, U.S., January 15, 2019. REUTERS/Kevin Lamarque/File Photo

The decision presents Barr, a veteran Washington insider, with his first major test since becoming the top U.S. law enforcement official last month, a position fraught with peril. Trump fired Barr’s predecessor Jeff Sessions in November after complaining for months over the decision by Sessions to recuse himself from overseeing the Russia investigation.

“I think Barr is in a terrible position from the standpoint of having two masters to please, each of which has a very different desire,” said Michael Zeldin, a former federal prosecutor. “He has a political nightmare on his hands.”

Mueller, who has headed the investigation since May 2017, is due to submit to Barr his confidential report on whether Trump’s campaign conspired with Russia and whether the Republican president has unlawfully sought to obstruct the probe.

Democrats, who have expressed concern Barr will try to shield Trump and bury parts of the report, already have threatened to subpoena it and go to court if necessary to force its release. Trump may pressure Barr to conceal damaging parts of Mueller’s report and release any findings that may exonerate him.

The Democrats took control of the House of Representatives in January and now wield subpoena power, with multiple committees investigating Trump’s actions. Republicans control the Senate. Mueller’s findings could be instrumental in any move in Congress to try to impeach Trump and remove him from office.

If the report includes “evidence of misconduct by the sitting president of the United States,” then “I think you have to believe the public interest is so extreme that there will be a mechanism for release, and I think Barr’s easy way out is to say, ‘It’s up to Congress,’” said Matthew Jacobs, a former federal prosecutor now with the law firm Vinson & Elkins.

Barr, 68, served as attorney general once before, from 1991 to 1993 under Republican President George H.W. Bush. He has embraced an expansive view of presidential powers. Last year, while Sessions was still attorney general, Barr sent an unsolicited memo to the Justice Department disputing Mueller’s authority to investigate Trump for obstruction of justice.

A ROAD MAP

From a legal standpoint, Barr has a road map in the form of the Justice Department’s regulations on the appointment of special counsels. Those rules require him to notify the top Democrats and Republicans on the House and Senate judiciary committees after Mueller completes his probe.

The rules do not require release of the entire report, but they do not explicitly prevent Barr from giving it to Congress. The rules also give Barr latitude to disclose parts of the report if it is in the public interest.

In deciding what to release, Barr may face thorny legal issues involving secrecy of grand jury testimony, protecting classified information, communications with the White House possibly subject to the principle of executive privilege shielding certain information from disclosure, and safeguarding confidential reasons for why some individuals were not charged.

Several Trump campaign figures already have pleaded guilty or been convicted in Mueller’s investigation, while others have not been charged. If the report provides evidence that Trump committed obstruction of justice or other crimes, Barr must decide how much should be revealed.

The Justice Department has a decades-old policy that a sitting president cannot face criminal charges, though some lawyers take issue with that conclusion. As a matter of policy, the Justice Department also does not give a public explanation for why any individual has not been charged.

“I don’t know that the department has ever encountered this situation where the reason a person isn’t being charged with a crime is that the person is immune by virtue of his office and is subject to impeachment as a result,” said Robert Litt, a former general counsel for the Office of the Director of National Intelligence who is now with the firm Morrison & Foerster.

“The more damaging the report is to the president, the greater the pressure is on Barr to release it, and paradoxically of course, if the report completely exonerates the president, then the president should want it released,” Litt added.

Barr appears to have support among rank-and-file Justice Department employees relieved to have an attorney general who understands the institution, after serving under former senator Sessions and then an acting attorney general, Matthew Whitaker, who was a Trump political loyalist. At a recent reception for employees, Barr bought the food and drinks and was greeted by people who told him they were happy he was there.

Barr “is an experienced lawyer and manager, and he has served in the position of attorney general, so he has great respect for that office,” said Mark Tuohey, a lawyer with the firm Baker & Hostetler who once served as deputy to former independent counsel Ken Starr on the Whitewater investigation involving Democratic President Bill Clinton’s business dealings.

“I don’t see this as a loyalty litmus test,” Tuohey added.