Watergate counsel Philip Allen Lacovara watched with keen interest the stunning move against F.B.I. Director James Comey by the Trump administration this week. Mr. Lacovara, a deputy to the Watergate special prosecutor Archibald Cox, was eyewitness in 1973 to the infamous Saturday Night Massacre when President Nixon’s order that Mr. Cox be similarly terminated led to the resignations of Attorney General Elliot Richardson and then acting A.G. William Ruckelshaus.

Those cascading resignations were perceived as a constitutional crisis at the time, but Mr. Comey’s dismissal, if it is indeed intended to throw off an F.B.I. investigation into possible Russian collusion with the Trump administration, represents a far graver threat to the republic than even the Watergate conspiracy, Mr. Lacovara says. That historic scandal involved a poorly executed spy operation against one political party by a faction within another. But the ongoing F.B.I. investigation of all the current president’s men, Mr. Lacovara points out, involves the intervention of perhaps the nation’s greatest international adversary into its internal affairs—worse, the possible collusion of members of the Trump team in that effort.

He describes Mr. Comey’s termination “not as clear cut” a case of executive overreach as Mr. Cox’s removal in October 1973 “but probably about equally as fishy.”

“There’s no doubt he has legal authority to fire Comey,” Mr. Lacovara says of President Trump, “just as President Nixon had the legal authority to fire Archibald Cox. So the issue is: What is the real motivation behind the dismissal?”

On that point Mr. Lacovara, a member of the America Media board of directors, is simply not buying the explanation offered by the Trump administration.

“It’s hard for me to credit that the president is now vigorously acting in Hillary Clinton’s interest,” he says. “The most plausible explanation is that this is an opportunistic excuse for getting rid of a guy who was conducting an investigation.”

That allegation seemed to gather credence just hours after Mr. Comey’s dismissal as media reported that Mr. Trump had been seeking to fire Mr. Comey for months. According to the press, Deputy Attorney General Rod Rosenstein only recently composed a memo justifying Mr. Comey’s termination under pressure from the White House. Mr. Rosenstein, apparently frustrated that his memo was cast publicly as the sole rationale for Mr. Comey’s dismissal, has threatened to resign, according to media reports on May 11.

Elliot L. Richardson (AP Photo, File)
Elliot L. Richardson (AP Photo, File)

The Associated Press reported on May 11 that just days before he was fired, Mr. Comey requested more resources to pursue his investigation into Russia’s election meddling and the possible involvement of Trump associates, fueling concerns in Washington that Mr. Trump was trying to undermine a probe that could threaten his presidency. According to the A.P., it is unclear if word of Mr. Comey’s request, put to Mr. Rosenstein, ever made its way to Mr. Trump.

The current president’s Nixonian gambit in firing Mr. Comey is “ingenious,” Mr. Lacovara says. It seizes upon legitimate criticism of the former F.B.I. director’s actions regarding the investigation into the use of then Secretary of State Clinton’s private email server “as the basis for getting rid of [Mr. Comey] in the midst of the Russian collusion investigation.”

The president’s move, he says, “pulls the fangs” out of the possible responses of Democrats who have complained for months that Mr. Comey acted unprofessionally during the election. In July, the F.B.I. ended its review without filing criminal charges but using the opportunity to criticize the Democratic candidate. Traditionally, prosecutors and investigators follow a “put up or shut up” policy at the end of criminal investigations, according to Mr. Lacovara, maintaining a professional silence when the evidence they have uncovered does not end in indictments.

At the time Mr. Comey’s actions had been enthusiastically supported by candidate Trump. He had urged the F.B.I. director to move even more aggressively against Ms. Clinton. But on May 10, the president used Mr. Rosenstein’s one-page memo criticizing Mr. Comey’s handling of the investigation to justify his firing. “It’s simply the latest example of how President Trump opportunistically changes his position to meet the perceived political needs of the day,” Mr. Lacovara says.

Mr. Lacovara is concerned that a Republican-controlled Congress has not demonstrated the will so far to aggressively run down the possible collusion of members of the Trump campaign with Russian operatives during the 2016 election. But he has looked to one of the other pillars of U.S. democracy, its career civil servants in the Justice Department and F.B.I., to assure that the matter would be pursued without prejudice. Now the move against Mr. Comey, coupled with the eagerness of Senate and House Republicans to overlook the Russian narrative while pressing for more aggressive actions against government leakers, has him worried.

Mr. Lacovara remembers the historic importance of the leaks authored by F.B.I. deputy director Mark Felt—who became known as “Deep Throat”—during the Watergate crisis.

“The Watergate affair would not have gone anywhere were it not for The Post repeatedly covering the story,” he says, “and [The Post] would not have been able to do that without the leaks from Felt.” He wonders if, perceiving that evidence of wrongdoing were being suppressed, contemporary public servants may not be as willing to take the same risks with careers or the threat of incarceration.

Mr. Lacovara is not convinced that even an aggressive congressional investigation would be sufficient to the task of exposing Russia’s hand in the 2016 elections, given its limited resources and expertise with criminal inquiries. Appointing a special prosecutor to supervise a thorough investigation with the assistance of career investigators from the Justice Department and F.B.I. would be the best outcome to the controversy stirred up this week. But Mr. Lacovara sees little likelihood that the attorney general’s office would make such a recommendation or that the Trump administration would countenance it.

In political survival mode, the president seems imperturbed about the effects of his lurching decisions. “He’s got his base,” Mr. Lacovara observes, “and he’s confident that he can ride this out.”

In the end, Mr. Lacovara argues, as political and civic institutions fail to fulfill their obligations, it may be up to the general public to keep the pressure on congressional representatives until the complete truth comes out about the 2016 elections, whether that exonerates Trump administration officials or further implicates them.

Kevin Clarke is America’s chief correspondent and the author of Oscar Romero: Love Must Win Out (Liturgical Press).