As the 50th anniversary of Watergate’s Saturday Night Massacre approaches on Oct. 20, I am struck by a parallel between that dramatic episode in the nation’s history and the more recent convulsions caused by the Jan. 6, 2021, riot at the US Capitol. In each misadventure, one key actor stepped forward to put the obligations of personal integrity and fealty to the rule of law above political ambition.

In Watergate, that man was Elliot Richardson.

In October 1973, Richardson was attorney general in Richard Nixon’s Cabinet. Nixon chose the straight-laced Boston Brahmin to repair the scandal-riven Department of Justice compromised by John Mitchell, Nixon’s longtime ally. But there was one hitch in the plan — in order to win confirmation by the Democrat-controlled Senate, Richardson had to agree to the appointment of an independent special prosecutor to take charge of the Watergate investigation. Richardson turned to his former Harvard law professor, Archibald Cox, stipulating that Cox could be fired only for “extraordinary improprieties.’’

Cox hired a staff to carry out his investigation and to prosecute any crimes that might be uncovered. Our top priority was whether there were higher-ups in the Nixon reelection campaign or administration who were involved in the planning or financing of the break-in and wiretapping of Democratic Party headquarters at the Watergate in June 1972.

The investigation was proceeding rapidly when White House aide Alexander Butterfield made the stunning revelation that Nixon had maintained a secret voice-activated electronic audiotaping system in the Oval Office and a variety of other locations used by the president. Presumably, that system would have captured conversations between the president and his chief aides that could provide decisive evidence of what Nixon and his lieutenants knew about Watergate skullduggery and when they knew it.

As Cox believed these tapes could resolve the questions about who was telling the truth about Watergate, he demanded recordings of selected meetings and phone conversations. A subpoena was served on the White House and ruled proper and enforceable by the district court and the federal Appeals Court. Yet Nixon refused to turn the tapes over. Instead he crafted a deviously clever plan to avoid producing the actual tape recordings.

Senator John Stennis of South Carolina was a conservative Democrat of considerable influence and standing. Nixon proposed to Cox that in lieu of the actual tapes, he accept summaries prepared by the White House and “authenticated’’ as accurate by Stennis. Among the many defects in the proposal was that under the rules of evidence such summaries (even if accurate) could not be used in place of the tapes in any subsequent trial. Moreover, Stennis, who was 72, was hard of hearing and was recovering from a recent mugging on Capitol Hill in which he had suffered a gunshot wound. Was he truly capable of listening to the original tapes and assessing whether the summaries to be provided to him by the White House were complete and accurate?

Later admissions by Stennis revealed that he misunderstood what the White House had represented about his role and that he was not physically capable of undertaking such an assignment, which was tellingly confirmed years later by Stennis’s personal physician.

The Nixon spin machine went into high gear — first falsely asserting that Cox had agreed to the “compromise,’’ then claiming that bipartisan congressional leadership supported it. Cox agonized over the looming confrontation with the president and labored over possible solutions short of our reviewing the actual tapes. For his part, Richardson urged Cox to make concessions to avoid escalating the confrontation with Nixon and (not incidentally) to save himself from acting on his promise to Congress to protect Cox’s independence.

Then came a final and entirely unacceptable condition from Nixon. Central to an eleventh-hour nonnegotiable proposal, Nixon demanded a promise from Cox that after agreeing to the “Stennis Compromise’’ terms, Cox would never ask for additional tapes or documents from Nixon. Clearly, had Cox acceded to this condition, the Watergate cover-up conspiracy would have achieved its goal of keeping the truth about Watergate from the American people.

Cox responded by holding a press conference at the National Press Club, explaining why he could not in good faith accept the limitations on his prosecutorial freedom imposed by the “Stennis Compromise,’’ while at the same time remaining true to the promise he had made to Congress and the American public to pursue a fair and vigorous investigation of Watergate. Cox’s televised performance was pitch perfect — it could not have been more convincing in logic or sincerity.

Richardson, an ambitious, talented man whose bright future included the possibility of a nomination by the Republican Party to contend for the presidency, faced the most perilous crossroads of his political life. Nixon ordered that, as attorney general, he must immediately fire Cox for continuing to pursue the subpoenaed tapes. Nixon emphasized his ultimatum with the full force of all the political pressure he could bring to bear on Richardson.

Although at times in the imbroglio Richardson may have seemed to bend, in the end he would not break. He told Nixon that Cox had committed no “extraordinary improprieties’’ but rather was properly following his promise to investigate vigorously. And with that, Richardson resigned as attorney general. Nixon tried again with Richardson’s deputy attorney general, William Ruckelshaus, who refused to fire Cox and was himself immediately fired by Nixon.

The Saturday Night Massacre evoked a firestorm of negative reaction from the American public and Congress. In firing the principled men who were swept off the Watergate chessboard for doing their sworn duty and refusing to compromise their personal integrity, Nixon had finally succeeded in turning public opinion against himself. The public rightly asked, “What was Nixon hiding?’’

History will record that Nixon’s decision to pressure Cox, Richardson, and Ruckelshaus backfired. The Saturday Night Massacre became Nixon’s self-immolation. If not for Cox and Richardson, among a small cohort of other patriots like Watergate judge John Sirica; Senator Sam Ervin of North Carolina, chair of the Watergate Committee; Representative Peter Rodino of New Jersey, chair of the House impeachment hearings; Katharine Graham, publisher of The Washington Post; and Leon Jaworski, who took over the helm as the next Watergate Special Prosecutor — each guided by honor, integrity, and respect for the rule of law — the outcome of Watergate might well have been different.

Almost 50 years after Watergate, another serious test confronted the nation. The enduring hallmark of democracy has been the peaceful transfer of power after a free and fair election. The winner of presidential elections is inaugurated and the losing candidate usually is gracious in defeat. Not so with Donald Trump.

Sitting at the pinnacle of a multitude of breaches of decorum, disrespect for American institutions, pathological narcissism, ignorance of history, and disdain for the rule of law that comprise Trump’s term of office was his desperate attempt to remain in office by whatever chicanery and thuggery he and his enablers could employ. On Jan. 6, 2021, he whipped up a violent mob of supporters with false claims and grievances and launched them at the US Capitol with the aim of disrupting and delaying the long accepted regular order by which presidential power is transferred.

I come now to the individual who to my mind parallels the principled stand taken by Elliot Richardson in Watergate: Trump’s vice president Mike Pence, a staunchly conservative former governor of Indiana and six-term member of the House of Representatives. As a running mate in 2016, Pence lent the morally challenged Trump the patina of his hard-right ideology and religious conservatism.

Once elected, Pence served Trump dutifully, never criticizing Trump, at least publicly, for his crudeness, self-regard, or dismissive attitude toward the ideals that most Americans (including Pence himself, I suspect) hoped to find in their highest elected leaders. But then came Pence’s moment of truth. When Trump pressured, cajoled, belittled, and threatened him to exceed his constitutional authority as vice president and refuse to certify Joe Biden as the duly elected new president, Pence said no.

As the tumult and deadly violence of the Trump mob spilled around him at the Capitol and his Secret Service detail whisked him to the safety of an armored limousine in the sub-garage below, Pence was aware of the cries of “hang Mike Pence’’ chanted by the mob that had overpowered Capitol Police and was lurching dangerously through the hallowed halls of the Capitol building. Pence refused the entreaties of his security detail to enter the limousine and escape the Capitol.

He had a solemn obligation to perform — his last as vice president — and by God he was going to do his duty and certify Joe Biden and Kamala Harris as the elected president and vice president. And after the mob was eventually ejected, Pence did just that. Had he acceded to Trump’s corrupt wishes, it is unclear what might have followed. We were a Pence away from chaos.

The calumny heaped upon Pence by Trump and his supporters has no doubt ended Pence’s career in national Republican politics. But history will treat him well, and we owe him a debt of gratitude.

While it is true that the United States fundamentally exists as a nation governed by laws, it is also true that we are dependent on the character of those who govern us and administer our laws. For if we are not vigilant and more careful in protecting what we have built, our democracy will not endure. History is littered with examples of democracies that once flourished and then failed.

As Benjamin Franklin was said to respond to a citizen who asked him upon leaving the Constitutional Convention in Philadelphia to describe the form of government that resulted from the Founding Fathers’ deliberations, “A Republic, if you can keep it.’’

That has always been, and still remains, the great challenge of the American experiment with a democratic form of government. The “you’’ in Franklin’s admonition is the “us’’ of today and tomorrow. It endures as our solemn obligation as citizens.

Richard Ben-Veniste was an assistant Watergate prosecutor and chief of the Watergate Cover-up Task Force. He also was a member of the bipartisan 9/11 Commission.