It may come as a surprise that one of this country’s greatest experts on Richard M. Nixon’s many crimes is, in fact, Hillary Clinton. In 1974 she was, by many accounts, among the brightest members of the staff of the House Judiciary Committee that investigated Nixon and prepared the articles of impeachment. In this bizarre election year, it must be painful to her that she should find herself at the center of a scandal described by her hyperbolic political opponent, Donald J. Trump, as “worse than Watergate.”

But while “Emailgate” is no Watergate, there are some noteworthy echoes.

For one, the controversial decision by the F.B.I. director, James B. Comey, to inform Congress about new evidence in the investigation into Mrs. Clinton’s email server makes sense only if you think of what Watergate meant for the bureau. Its reputation was badly hurt by the behavior of L. Patrick Gray, its acting director at the time, and the revelations of its Hoover-era misdeeds that followed. Subsequent directors like William H. Webster, Robert S. Mueller III and now Mr. Comey have all appeared to understand that the country needs a trusted, nonpartisan F.B.I.

The fact that emails on Anthony Weiner’s computer might be relevant to the investigation into Mrs. Clinton’s private email server had to be reported to an interested congressional investigative committee. If Mr. Comey had sat on the information — with part of the country already voting in the presidential election — he would have not only made the F.B.I. more of a target for partisan fury, but also made himself a target for future House investigations, since he had testified under oath that the F.B.I. had completed its Clinton email investigation.

And there is another useful comparison to Watergate. As is clear from the F.B.I.’s investigation thus far, Mrs. Clinton and her team’s explanations of the handling of the server still seem, at best, incomplete. She ran the State Department too well for incompetence by her inner circle in handling government emails to explain everything. Perhaps as a result of scars from Republican witch hunting of the 1990s, Mrs. Clinton turned a blind eye because she did not trust civil servants to maintain her privacy. Despite the noisy, partisan chatter on the issue, the public deserves a better explanation.

I do not come at this just as a historian; for five years I supervised a group of archivists at the Nixon library, members of a profession who deal every day with balancing the public’s need and desire for official transparency with the authority of government departments to decide when their materials can be declassified. ...