Editorial: Pardoning Manafort would be unambiguous grounds for impeachment. Take it off the table, Mr. President

President Trump has attacked special counsel Robert S. Mueller III and the investigation into Russian election meddling so often and so disgracefully that it can be difficult to sustain a sense of outrage. But Trump’s statement on Wednesday that a presidential pardon for his former campaign chairman Paul Manafort is “not off the table” is an alarming escalation in his efforts to undermine that probe and, more generally, the rule of law.

For months, Trump has denounced the investigation as a “witch hunt,” steadily feeding a self-serving narrative in which prosecutors are corrupt and untrustworthy and the legal process is not to be believed. Along the way, he has fired his FBI director over “this Russia thing” — and more recently, pushed out his attorney general, who had angered the president by (rightly) recusing himself on the Russia probe. This week, Trump tweeted that prosecutors were “viciously” urging witnesses to lie.

But to signal so brazenly, as he did on Wednesday, that silence or lack of cooperation on Manafort’s part could eventually be rewarded with a presidential pardon is especially appalling.

If Trump is rash enough to actually grant a pardon to Manafort or to others who have been caught up in Mueller’s dragnet, that should immediately trigger an impeachment investigation by the House of Representatives.

Trump no doubt would justify clemency for Manafort on the grounds that, as the president has asserted without evidence, Mueller is a politically motivated prosecutor whose investigators have treated people “horribly & viciously” and ruined their lives “for refusing to lie.” Another interpretation, of course, would be that Trump was using the pardon power to reward Manafort for not implicating him in wrongdoing related to Russia.

Manafort’s actions have contributed to the speculation that a pardon might indeed be on the table. After he was convicted of financial crimes related to his work as a political consultant in Ukraine, he avoided a trial on additional charges by accepting a plea bargain that required him to pledge full cooperation with Mueller. But on Monday the special counsel announced that after Manafort signed his plea agreement, he “committed federal crimes” by lying to the FBI and the special counsel’s office “on a variety of subject matters.”

That’s not all. On Tuesday, the New York Times reported that one of Manafort’s lawyers had repeatedly briefed Trump’s attorneys about Manafort’s conversations with federal investigators after Manafort agreed to cooperate with Mueller. Legal experts have called that a violation of legal norms.

You don’t have to be a conspiracy theorist to suspect that all these developments are related. After pushing Jeff Sessions out of the Justice Department, Trump did not take the obvious step of of designating Deputy Atty. Gen. Rod Rosenstein as acting attorney general. Instead, he installed Sessions’ chief of staff, Matthew Whitaker, who was critical of the Mueller probe before he joined the administration. That clearly threatens the credibility of the investigation.

For the moment, Mueller has been proceeding on several fronts, including an exploration of whether Trump associate Roger Stone is linked to WikiLeaks and the release during the 2016 campaign of Democratic Party emails hacked by Russians. (Stone has denied any wrongdoing.) On Thursday, prosecutors announced that Michael Cohen, Trump’s former lawyer and “fixer,” had pleaded guilty to lying to Congress about when discussions about a possible Trump real estate project in Moscow came to an end.

Given these developments, Trump might be tempted to take action against Mueller from which he so far has reluctantly refrained.

Congress could provide an insurance policy for Mueller by passing the Special Counsel Independence and Integrity Act, which would codify a Justice Department rule that special counsels can be fired only for good cause and would allow a counsel to appeal his or her dismissal in court. But on Wednesday, GOP leaders in the Senate blocked a vote on the bill.

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The ultimate check on Trump committing his own version of Richard Nixon’s “Saturday Night Massacre” is the threat of an impeachment investigation. A presidential pardon may not be reviewable by Congress or the courts, but an impeachment inquiry would have a duty to determine whether the pardon power had been used to perpetuate a cover-up.

Trump repeatedly has insisted that there was “no collusion” between Russia and his campaign. If the president is confident of his innocence, he should stop the disgraceful attacks on Mueller and expeditiously nominate a new attorney general whose impartiality when it comes to the Mueller investigation can’t be questioned.

As for pardons for those the special counsel has prosecuted, Trump must take them off the table. The only message he should be sending to Manafort and others caught up in Mueller’s investigation is to tell the truth and accept the consequences.

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