Congress may be unable to provide any job protection legislatively for special counsel Robert Mueller, whose wide-ranging investigation into Russian meddling in the 2016 election continues to anger President Donald Trump.

While Trump confidant Roger Stone was defending himself in front of a separate committee elsewhere on Capitol Hill, legal scholars offered competing views on whether two Senate bills designed to protect Mueller from firing by Trump or someone in the Justice Department would pass constitutional muster during a hearing of the Senate Judiciary Committee.

A bill sponsored by North Carolina Republican Thom Tillis and Delaware Democrat Chris Coons would allow a fired special counsel to have his dismissal reviewed by a three-judge panel within 14 days. Another measure, put forward by Lindsey Graham, R-S.C., and Cory Booker, D-N.J., would require the Justice Department to clear such a firing with a panel of judges before it could take effect.

“The bills in their current form are unwise and unconstitutional,” said Akhil Reed Amar, a constitutional law professor at Yale Law School and a Democrat who publicly opposed Trump in the election.

Eric Posner, also no fan of Trump, disagreed. “I’ve concluded they do not violate the principle of the separation of powers and on the contrary advance important constitutional values,” said Posner, a professor at the University of Chicago’s law school.

John Duffy, a law professor at the University of Virginia and former clerk of the late conservative Supreme Court Justice Antonin Scalia, argued that parts of both bills were legally questionable, but said they could be tweaked to help pass judicial reviews. He, however, declined to offer an opinion on how the Supreme Court might view them.

“With such judicial variability, I have to balk,” Duffy said.

The complex legal issues and the scholars’ differing perspectives seemed to give senators pause about how, or whether, to move forward.

The law professors referenced almost a dozen Supreme Court cases, most notably Morrison v. Olson, a 1988 decision that held the Independent Special Counsel Act was constitutional.

“It’s hard to make a point of what’s constitutional,” said the panel’s chairman, Charles Grassley, R-Iowa.

Tillis agreed to make changes to his bill, including removing a line that would make his legislation retroactive to Mueller’s hiring date.

“This is about checks and balances. This is about the Senate asserting its authority,” said Tillis, who stressed his support for Trump during and after the hearing.

But he acknowledged the committee has plenty on its calendar and was uncertain about when the bills might be back before the panel.

Trump has repeatedly called the Russia investigations — besides Mueller’s, the Senate has two probes ongoing and the House one — a “hoax.” During the summer Trump was reported to be considering asking Deputy Attorney General Rod Rosenstein to fire Mueller — prompting senators to draw up legislation.

In August, Trump said he wouldn’t fire Mueller. Trump probably doesn’t have the authority to do so directly, but he could ask a high-ranking official at Justice, like Rosenstein, to do it.

“We’re trying to make sure something out bounds doesn’t happen, and Mr. Mueller can proceed with some confidence,” Graham said. “What I’m trying to avoid is a Saturday Night Massacre and the upheaval in the nation. … I want the president to know there is a process in place. There are checks and balances long before you got here and they’ll be here long after your gone.”

The Saturday Night Massacre refers to former President Richard Nixon’s decision to fire independent special prosecutor Archibald Cox during Watergate. The Attorney General and his deputy both resigned rather than carry out Nixon’s order. Finally, Solicitor General Robert Bork fired Cox.

In the end, said Wake Forest professor Katy Harriger, Congress’ very public support for Mueller might be more important than passing one or both of the bills.

“The much more important thing it did was sort of put the president on notice that there’s bipartisan support for Mueller,” said Harriger, author of “The Special Prosecutor in American Politics.” “He may have the constitutional authority, if he can find someone in the Department of Justice to do it,” she added. “Mueller is not protected from that right now, except by politics.”

Meanwhile, Roger Stone testified to the House Intelligence Committee behind closed doors. Monday evening he issued a statement accusing panel members, particularly Democrats, of making “false allegations” about collusion between the Trump campaign and the Kremlin.

Mueller appears to be making progress in his investigation, which seems focused, for the moment, on former Trump campaign chief Paul Manafort. The special counsel has also asked for numerous emails and notes about the firing of former FBI Director James Comey, according to reports.

James Comey was fired as the FBI’s director in May prompting the appointment of Special Counsel Robert Mueller to investigate Russia’s meddling in the 2016 election. As Mueller’s investigation into whether Donald Trump’s campaign or associates colluded with Moscow moved into a more serious phase, the White House’s press secretary Sarah Huckabee Sanders has made several statements about Comey from the podium. Here are some of her remarks from September 2017.