Amid impeachment calls and a disputed report, Trump sends a rare message to Mueller: Thank you

Go ahead, take Robert Mueller's word for it.

So implied U.S. President Donald Trump on Saturday when he took the unusual step of thanking Mueller's office, which is investigating Russian collusion in the 2016 election. The expression of gratitude came after Mueller's office issued a rare statement of its own, disputing aspects of a report alleging Trump directed his former fixer to lie to Congress about a Moscow real-estate deal.

At the White House on Saturday, Trump was gracious.

"I appreciate the special counsel coming out with a statement last night," he said. "I think it was very appropriate that they did so. I very much appreciate that."

One of the more interesting developments overnight is the newfound confidence Team Trump has expressed about Mueller's integrity- Josh Campbell, former FBI agent

Mueller's office on Friday described aspects of a BuzzFeed News report as "not accurate," after the news outlet reported that Trump instructed his longtime personal lawyer Michael Cohen to lie to Congress about a deal to build a Trump Tower Moscow.

The statement reads, in full: "BuzzFeed's description of specific statements to the Special Counsel's Office, and characterization of documents and testimony obtained by this office, regarding Michael Cohen's Congressional testimony are not accurate."

The special counsel's office has not elaborated on specifics about what it is disputing. BuzzFeed is standing by its story.

But Trump's message of appreciation was an unusual sentiment from a president who has persistently decried Mueller's work as a "witch hunt." To some observers it comes off as validation of the lead investigator's trustworthiness. That irony was not lost on the president's critics.

"For those of us who've been defending Mueller's team and DOJ against utterly unfounded attacks from Trump and his supporters, it's great to see Team Trump now citing Mueller's office as, not only a credible, but even an authoritative truth-teller," conservative commentator Bill Kristol tweeted.

Former FBI special agent Josh Campbell noted wryly that he also didn't see Trump's change of heart coming.

"One of the more interesting developments overnight is the newfound confidence Team Trump has expressed about Mueller's integrity. After endless attacks, they suddenly embrace his honesty."

Whether the White House embraces Mueller's final report "with the same reverence" is another question, Campbell said.

It was only two months ago that Trump erupted over Twitter, calling Mueller's work a "total mess."

BuzzFeed allegations a bombshell, if true

For the president, publicly praising Mueller now risks instilling public faith in his Trump-Russia investigation a risk that might be worth it if it can tamp down growing impeachment calls that surfaced after BuzzFeed posted its story late Thursday. If true, the report by two seasoned investigative journalists would be a bombshell, directly implicating Trump in a crime, and amounting to the kind of black-and-white revelation of obstruction of justice that would be impossible to dismiss.

Two Democratic chairs of House committees vowed to investigate the report. Depending on its accuracy, the report was seen as a potential precursor to a vote to impeach, according to some senior lawmakers, including Independent Vermont Sen. Bernie Sanders and Texas Democrat Rep. Joaquin Castro.

There's no debate that the allegations described in the report would constitute a crime. Not even William Barr, Trump's nominee to be attorney general, would dispute that, noted Jonathan Turley, a leading constitutional scholar who testified this week during Barr's Senate confirmation hearings.

"One of the things I discussed, and one of the things [Barr] discussed in the Senate is how suborning perjury would be a clear federal crime of a president, but also a possible basis for obstruction of justice," Turley said in an interview.

"William Barr specifically already addressed that issue."

An exchange between Democratic Sen. Amy Klobuchar and Barr this week crystallized Barr's views.

"You also said that a president or any person convincing a witness to change testimony would be obstruction, is that right?" Klobuchar asked.

"Yes," Barr testified.

Questions about the BuzzFeed report

It isn't known how "bulletproof" the BuzzFeed report is, noted Dave Levinthal, who leads the federal politics reporting team at the Center for Public Integrity in Washington, D.C.

"It's entirely possible that there are elements of the story that could be wrong, and others fundamentally true. And that's an open question right now," he told CBC News Network on Saturday.

On the other hand, if the reporting bears out, then an impeachment inquiry is bound to happen, said Allan Lichtman, a political forecaster with American University and the author of The Case for Impeachment.

"We can certainly start an impeachment inquiry in the House Judiciary Committee because it's their duty to investigate."

The reported allegations could be the "smoking gun," Lichtman said, as directing Cohen to lie under oath to Congress would be suborning perjury and possibly witness tampering. It would also make for a "plain, slam-dunk" case for those crimes as well as for conspiracy and likely aiding and abetting perjury, tweeted Sen. Sheldon Whitehouse, a member of the Senate Judiciary Committee.

There have been two cases of modern-era impeachment proceedings for Richard Nixon and Bill Clinton. The article of impeachment that drove the process for Nixon by the House Judiciary Committee in 1974 concerned his attempt to suborn perjury from those involved in the Watergate break-in.

Clinton was impeached for committing perjury over an extramarital affair, with Republicans arguing that perjury is perjury, no matter the underlying substance.

Trump facing other allegations

"But in the Clinton case, we were talking about covering up a private sexual affair, not covering up the subversion of our democracy with Russia," Lichtman said. "This seems a thousand times more serious."

In light of the special counsel's statement, open talk of impeachment could begin to calm.

But outside of the BuzzFeed report, there are already strong allegations that the president violated campaign finance laws, with respect to the payment of hush money to pornographic actress Stormy Daniels. Stories that Trump committed crimes could begin to make people "feel antsy" about holding off on impeachment procedures, said William Yeomans, who served 26 years in the U.S. Department of Justice.

As the legislative check on the presidency, he said, congressional Democrats will be compelled to exercise their constitutional obligation to launch an inquiry at least to determine whether impeachment is appropriate.

If the report is corroborated in a credible way, he said, "I think the pressure is going to mount to start an impeachment inquiry. I think it has to."

Senior Democrats have been loath to discuss impeachment so openly because of the political problems it could present.

Caution around impeachment

Impeachment is a political process that must be approached with caution, and shouldn't be used merely as a mechanism to brand someone with a "scarlet letter," but to oust that person from office, said Susan Low Bloch, a professor of constitutional law at Georgetown University who testified during the Clinton impeachment proceedings.

"The House shouldn't start unless it's pretty clear there's enough evidence to not just impeach him, but to convict, and remove him," she said. "Otherwise, you have this sort of wounded warrior running around, and it's not healthy for the country."

Removal from office still requires a two-thirds vote to convict the president in the Senate, which is under Republican control and thus unlikely to support such a move.

Legislators considering the disputed report will be looking for corroboration that goes beyond just Cohen's word, given how tainted his reputation has become. Cohen has already pleaded guilty to lying to Congress. He is now co-operating with Mueller's investigation into Trump's alleged campaign collusion with the Russians.

Turley noted that Cohen, "a serial liar and a felon," represents a major liability for the report's credibility. All of which makes Cohen's scheduled appointment to testify before Congress on Feb. 7 more interesting.