Despite the efforts of my grandfather and his investigators, and those of the media and Watergate committees, basic questions about the scandal remain unanswered. It is still unclear what, if any, advance knowledge Nixon had of the break-in. Though the president is on tape approving hush money payments to the defendants, it remains unknown whether he personally played a role in raising the funds. For that matter, the degree to which H.R. Haldeman, the White House chief of staff, and Attorney General John Mitchell directed illegal activities on a day-to-day basis has not come to light.

Such questions, of course, are analogous to those currently faced by the Jan. 6 committee.

Richard Ben-Veniste, one of my grandfather’s top deputies who was at the reunion, said he was asked by the Jan. 6 committee to offer advice. “Jan. 6 was the Saturday Night Massacre on steroids,” he said. “It was far more dangerous than what we thought was unthinkable: the appearance of a coup d’état when raw power replaced the rule of law. Nixon, for all his criminality and authoritarian sensibilities, possessed a sense of shame.”

The continuum that stretches from Watergate to the present features a few ironies. During and after the Nixon scandals, congressional checks on executive power were enacted, including the War Powers Act of 1973 and modifications to the Federal Election Campaign Act. Those legislative initiatives led to charges of overreach and a counter-movement by some Republicans who wanted to restore power to the executive branch.

One of them, a former Nixon White House aide named Dick Cheney, was elected to Congress four years after Nixon’s resignation. Mr. Cheney, of course, was vice president during the George W. Bush administration and his daughter, Liz Cheney, is the vice chair of the Jan. 6 committee who has sharply criticized Mr. Trump as an abuser of executive power.

An additional irony following Nixon’s secretive presidency was the push for greater transparency in government: more sunlight, less smoke-filled rooms. But that effort has not necessarily translated into more efficient governance. To take a recent example, House conservatives led by Representative Marjorie Taylor Greene, the far-right Georgia freshman who was born three months before Nixon’s resignation, have used the virtue of legislative transparency as an argument for slowing the House Democrats’ agenda by insisting on roll call votes for everything on the legislative calendar.

At the reunion, Representative Deborah Ross, a North Carolina Democrat, was mingling among the guests as she recalled listening to the Senate Watergate hearings at the age of 10 while driving cross-country in her family’s station wagon. Noting the coincidence of the Watergate anniversary taking place in the middle of the Jan. 6 committee hearings, Ms. Ross said that “the obvious thing the two scandals had in common was that we’re talking about two men who wanted to hang onto power no matter what. The irony is that Nixon would have won in 1972 anyway, if he hadn’t been so paranoid about the Democrats.”