A 1973 political cartoon by Jean-Claude Suares depicts a huge reel of audio tape crashing into the White House.Corbis Historical / Getty Images

Richard Nixon needed a reason.

He’d resolved to fire Archibald Cox, the special prosecutor investigating his involvement in Watergate, more than three months before the Saturday Night Massacre, when Cox was eventually dispatched. It was only a matter of time until Nixon would find a suitable pretext to give him political cover—and soon, Cox gave him one. The investigator refused to accept a so-called compromise on Nixon’s secret White House tapes, whereby Cox would receive summaries of the recordings instead of the tapes themselves. The former president quickly moved to remove Cox from his post, and to dissolve the office of the special prosecutor itself.

This fraught period of the Watergate affair—which involved an elaborate, president-sanctioned cover-up in the aftermath of a break-in at the Democratic National Committee headquarters—is the closest historical parallel to the current moment. Like Nixon, President Trump appears eager to fire the man investigating campaign and White House officials’ culpability in a high-profile scandal: Robert Mueller, the special counsel examining a broad range of subjects related to Russian interference in the 2016 election. And like Nixon, Trump seems one false move away from following through.

In 1973, I worked as a lawyer on Cox’s task force investigating obstruction-of-justice allegations against Nixon. The White House tapes show that, by the summer of 1973, the president had grown increasingly frustrated over Cox’s examination of alleged misconduct, which included a conspiracy to obstruct justice by the president’s closest aides. Cox’s dogged pursuit of nine specific tape recordings was the last straw. The special prosecutor wanted the audio for a reason: Ever since White House Staff Secretary Alexander Butterfield had revealed the existence of Nixon’s voice-activated taping system, in July 1973, Cox hoped to use the recordings to resolve disputed facts about who said what in conversations with the president.

Yet Nixon refused to turn them over—even after he was subpoenaed by a grand jury and under orders from two separate courts. Instead, the president proposed that Cox accept the compromise, under which he would receive summaries of the taped conversations prepared by Nixon. Cox’s refusal to agree to any substitute for the tapes themselves provided Nixon the pretext he was seeking to remove the special prosecutor, and to return the investigation to more pliant personnel within the Justice Department.

The nation correctly perceived that Nixon’s true intention was to prevent Cox from uncovering evidence of criminal misconduct that Nixon was determined to keep hidden. While Trump’s true intentions remain unknown, his feelings about Mueller, at least, are crystal clear—he hasn’t tried to hide them. In multiple public statements, he and his associates have condemned Mueller’s investigation, and one of his lawyers went so far as to say the inquiry should be shut down.

As with Cox, Mueller and his staff have done nothing publicly known that would provide a legitimate reason to justify dismissal: They do not appear to be the source of leaks to news media, nor have they committed any known improprieties. Instead, Mueller has been methodically investigating under the mandate he was given and is building out cases in multiple directions.

Trump seems to have reached breaking points with Mueller before. In June, he reportedly instructed White House Counsel Don McGahn to orchestrate Mueller’s firing, only to back off when McGahn threatened to resign. On Tuesday, The New York Times reported that a similar episode happened in December, when the president erupted in anger over an erroneous news article wrongly attributing certain subpoenas of financial documents to Mueller’s probe. Again, Trump’s immediate impulse was to fire Mueller, according to the Times.

There’s nothing to suggest Trump has changed his mind about the Mueller inquiry in the months since. To the contrary, Trump raged this week over investigators’ latest target: Michael Cohen, a New York lawyer who’s long functioned as the president’s fixer and who allegedly paid off women who claim they had affairs with Trump. Hours after the FBI raided Cohen’s home, office, and hotel room, Trump called the Mueller probe a “disgrace” in comments to reporters, telling them that “many people have said, ‘You should fire him.’”

Deputy Attorney General Rod Rosenstein’s involvement in the raid—he green-lit Mueller’s referral of Cohen’s case to federal investigators in New York—has poured gasoline on an already blazing fire of indignation raging in the White House. It’s reasonable to wonder whether Trump, in an unwitting echo of Nixon, could try to replace Rosenstein with a more malleable appointee—one who could act to rein in Mueller and other investigators without the president taking the political risk of firing him himself. According to recent news reports, Trump is considering just this plan.

Cox’s dismissal 45 years ago was the beginning of the end for Nixon. The impeachment resolutions introduced in its aftermath continued to gain momentum as more and more evidence of Nixon’s guilt accumulated—until Nixon resigned in disgrace. Firing or hobbling Mueller could precipitate a similar firestorm of public protest, perhaps matching the backlash against the Saturday Night Massacre in its scope and intensity.

Despite the myriad similarities between Watergate and Russiagate, however, the major distinction remains that majority control of both houses of Congress rests with the Republican Party. Up to now, GOP congressional leaders, like Mitch McConnell and the soon-to-be-replaced House speaker, Paul Ryan, have been silent as to what consequences would befall Trump if he acts against Mueller and his investigation. But protecting the rule of law should provide Republicans sufficient motivation to declare that any Trump intervention is unacceptable.

Despite that recent silence, it’s possible the tide is beginning to turn. On Wednesday, four senators introduced bipartisan legislation to protect Mueller. And on Tuesday, Senator Charles Grassley, the powerful chairman of the Senate Judiciary Committee, told CNN it would be “suicide” for the president to fire him. If Trump has, indeed, decided to remove Mueller once and for all, perhaps only a credible threat of impeachment will deter him.

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