Robert Mueller's appointment as a special counsel to oversee the Justice Department's investigation of Russia's interference in the 2016 presidential election does not in any way preclude muscular congressional oversight into the matter.
Nor does it give congressional witnesses carte blanche to duck questions they do not feel like answering in public.
Within hours of the announcement about Mueller, Republican members of Congress started using his leadership of the investigation as an excuse to stand down.
“You’ve got a special counsel who has prosecutorial powers now, and I think we in Congress have to be very careful not to interfere," Sen. Lindsey Graham (R-S.C.) told reporters on Thursday. "Public access to this is probably going to be very limited now. It’s going to really limit what the public will know about this.”
And one of several congressional witnesses-in-waiting cited Mueller as an excuse not to answer even basic questions from his ostensible congressional overseers. Deputy Attorney General Rod Rosenstein, who played a highly controversial role in Comey's firing, briefed Senate and House members last week -- in a closed session, despite the lack of any discussion of classified material.
“Basically any question of any substance, it was, ‘I can’t comment because it may be the subject of an investigation by Mueller,’ ” Sen. Jeff Merkley (D-Ore.) told the New York Times.
Rep. Lloyd Doggett (D-Teaxs) said in a statement that "the most frequent answer I heard to questions from members of either party was 'I cannot answer that question.' He declined to answer any question concerning his personal conduct, motivation, or the circumstances of the firing of FBI Director James Comey, indicating that even this could be within the scope of the Mueller investigation."
But precisely as Graham indicated, Mueller's investigation will be secret. It will also be unhurried – certainly by the standards of the modern news cycle. In fact, it might never result in any public disclosure at all.
For comparison's sake, it took special counsel Patrick Fitzgerald nearly two years of investigating the leak of Valerie Plame's identity as a CIA operative to bring obstruction of justice charges against former vice presidential aide Scooter Libby; there were six more months until trial; and even then Fitzgerald only revealed a fraction of what his investigation had turned up. Any number of highly damning indications that Dick Cheney was directly involved remain undisclosed to this day, because Libby's obstruction prevented prosecutors from charging anyone else. And unlike investigations pursued under the previous "independent counsel" statute, there was no "final report" to Congress.
"Congress shouldn't roll over," said Nick Schwellenbach, director of investigations at the Project on Government Oversight (POGO). "Whatever Mueller does, it's going to be focused on whether laws were broken or whether there was any criminal activity, but there could easily be noncriminal activity that the public needs to know about," he said.
Even the most overt collusion with the Russians might not technically be a criminal act, or "there may not be enough evidence, or it may not be easy to establish criminal intent," he said.
And while Mueller is only pursuing possible criminal charges, Congress has a much broader mandate, which includes informing the public and considering legislative remedies. That is why Congress did not leave the response to the 9/11 terrorist acts to the independent commission or the executive branch.
Five congressional committees are currently in some stage of investigating Russian interference in the election: the Senate Intelligence and Judiciary committees, and the House Intelligence, Judiciary, and Oversight committees. Meanwhile, Democrats are calling for an independent, 9/11-style commission in addition.
The Senate Intelligence Committee has issued a subpoena to former national security adviser Michael Flynn -- although on Monday he refused to comply, unless granted immunity from prosecution.
Ousted FBI Director James Comey is expected to testify before that committee sometime after Memorial Day.
The House Oversight Committee has requested FBI documents or recordings related to Trump's communications with Comey, and any White House accounts of the Oval Office meeting where Trump spoke about Comey's firing with Russian visitors.
Former CIA Director John Brennan appears before the House Intelligence Committee on Tuesday. Brennan expressed concerns about Russian interference in the election last summer.
A Washington Post report Monday night that Trump and other White House officials asked Daniel Coats, the director of national intelligence, and Adm. Michael S. Rogers, the director of the National Security Agency to push back against the FBI investigation suggests more such requests are in the offing.
Meanwhile, the ongoing investigation that Mueller is inheriting shows signs of heating up, with the Washington Post reporting that the FBI "has identified a current White House official as a significant person of interest."
Comey is likely to be the first major witness before any of the committees, and how his hearing goes will tell us a lot about how assertively and effectively Congress will act.
Comey's last appearance was on May 3 before the Senate Judiciary Committee, where the main topic was his decision to notify Congress about new emails in the Hillary Clinton investigation just before the election. The questioning was somewhat haphazard.
But when Comey appears this time – as a witness to his own controversial firing, the senators and their staffs need to be ready to provide the public with a clear narrative, a supporting chronology, concrete evidence and straightforward "Did this happen or did it not?" questions for Comey.
"Before Comey's testimony, there's a whole series of documents and evidence they should try to obtain -- or ascertain if it doesn't exist," said Jenny Durkan, who served as U.S. Attorney for the Western District of Washington from 2009 to 2014.
"At least then you have the contours about which you want to ask questions and to explain the narrative to the people. The chronology of events is going to be critical," she said.
For instance, here is one possible chronology: Trump becomes aware that there is an active criminal investigation of Russian intervention that extends to his national security adviser Michael Flynn; he asks Comey to back off; it becomes clear that Comey is not doing that; Trump fires Comey.
"And then if he brags to the Russians, 'I fired him it's all good,' it's more than a prima facie case," Durkan said.
"When you see it lined up chronologically, it's very compelling."
And if Comey or other witnesses decline to answer a direct question – as they already have, many times – they should be forced to explain why.
There are many reasons a witness – particularly past or present law enforcement – could legitimately decline to answer a question. For instance, some of the information in the Russia investigation appears to have been derived from surveillance of suspected foreign spies within the United States conducted under secret Foreign Intelligence Surveillance Court warrants, so that information is presumptively classified. The Department of Justice has strict rules about disclosing information uncovered during an ongoing criminal investigation – and violating grand jury secrecy is a criminal offense.
Witnesses who fear that their answers could incriminate them can of course assert their Fifth Amendment rights to remain silent.
But witnesses who just would prefer not to answer need to be pressed.
"You can put some heat on them," said Barbara McQuade, who was asked to resign in March from her position as U.S. Attorney for the Eastern District of Michigan.
She suggests a tough approach: "This isn't classified, right? This isn't grand jury material, right?" And if the answer is evasive, "you could push it: How would that in any way affect the outcome of a criminal investigation? The public has a right to know that. If it's classified, obviously you can't talk about it. But if it's simply a matter a grand jury is interested in, it's not really protected."
Questioning the basis for a witness's refusal to answer could be as revelatory as the answer. Why exactly do they think classified information is involved? How certain are they that the information is classified? Do they feel there is some sort of ethical prohibition against answering? What would that be? Have they promised someone they would not talk about the subject? Is there some department rule that prohibits them from answering? What rule is that?
Alternately, if the committee staff has done its job, senators will not only get answers to their questions, but know the answers before they ask them.
Comey in particular has been amenable to that approach in the past: The testimony that made his reputation as a straight shooter was teed up by committee staff at a May 15, 2007, hearing. Responding to questioning by Sen. Chuck Schumer (D-N.Y.), Comey told a gripping story about his high-speed race to then-Attorney General John Ashcroft's hospital bedside and the ensuing standoff with senior White House aides over the administration's warrantless wiretapping program.
There was nothing spontaneous about it. As the New Yorker reported in 2016, Comey had already been debriefed by Preet Bharara, the now-fired U.S. Attorney from the Southern District of New York, who was then a top Schumer aide.
"It will be interesting," Durkan said, "if the White House, on the grounds of executive privilege, will prohibit Comey from discussing any conversations he had with President Trump."
Durkan said she suspects Trump is "probably regretting" that White House did not invoke the privilege to prevent former Acting Attorney General Sally Yates's damaging testimony about her conversations with White House Counsel Don McGahn about national security adviser Michael Flynn's vulnerability to Russian blackmail.
The doctrine of executive privilege is intended to protect confidential deliberations within the executive branch from compelled disclosure, so that the president receives candid advice from aides. It can be invoked by the White House to prohibit testimony even from witnesses who would otherwise be happy to talk. But its scope has never really been defined – and its invocation is always controversial.
"I think politically it will be very difficult for Trump to assert it and I think there would be pressure to litigate it," Durkan said.
It is "fair game" to ask about the reasons for Comey's firing, McQuade said. "Trump himself has said it was the Russians. You can't invoke executive privilege if you've waived it, and speaking on television about a topic would seem to me like the ultimate waiver.”
The Washington Post reported last week that Rosenstein, in his talk with senators, was "unequivocal" that the Senate Intelligence Committee should continue its own investigation despite Mueller's appointment.
But Mueller himself is likely to ask the committees for some deference – or at least some cooperation.
"I think that Bob Mueller will try to protect as much of the discussions as he can," said Durkan.
For one, all prosecutors hate seeing their potential prosecution witnesses making multiple public statements, because any discrepancies can be exploited by the defense. "Someone can make a lot of hay with that on cross examination," said McQuade. "If I'm Mueller, I would really rather have everyone talk to me. But there's such a strong public interest here I can't imagine senators would be satisfied with that."
In fact, congressional and law-enforcement investigations have often run concurrently; examples include Watergate, Iran-Contra, Whitewater, and 9/11. "There's always that tension between the public investigations by the Hill and the criminal investigations by the prosecutors at the Department of Justice," Durkan said.
But Congress generally mitigates the risk by coordinating with the special counsel before calling witnesses. The Washington Post recently reported that committee leaders have already been talking with senior Justice Department officials to “deconflict” their efforts.
And House Oversight Committee Chairman Jason Chaffetz tweeted Monday that Comey wants to speak to Mueller directly before making any public statements.
Flynn could be the first test case of what happens when witnesses refuse to cooperate with the congressional investigation for fear of the criminal one. In the letter they sent to the Senate Intelligence Committee on Monday, his lawyers said that without "assurances against unfair prosecution," he was invoking his Fifth Amendment privilege not to turn over the documents the committee had subpoenaed.
Congress could pursue contempt charges against Flynn. Another option is to grant him immunity.
That strategy notoriously backfired during the Iran-Contra scandal when Lieut. Col. Oliver North was given congressional immunity for his testimony. His conviction in federal court on charges that included aiding in the obstruction of Congress and destroying documents were thrown out after special prosecutor Lawrence Walsh was unable to prove that they had not been influenced by his congressional testimony.
Senate Intelligence Committee Chairman Richard Burr said on Monday that "immunity is off the table."
But, said Schwellenbach, "If you want to immunize the small fish to get the big fish that's definitely a worthwhile strategy." The secret is: "You want people to actually flip on the boss."