“No group of prosecutors and supporting personnel ever have labored under greater public scrutiny,” the special counsel report declares on its opening page. “Every decision seemed to be a delicate one and previously uncharted courses frequently had to be faced. Each action occurred in the midst of a national turmoil.”

It was 1975, and the Watergate Special Prosecution Force had just issued a lengthy report after 28 months investigating Richard Nixon’s administration and his campaign. Let it not be said we’ve never been here before.

They form an odd American literary genre: reports by special counsels and select congressional committees on presidential wrongdoing. They carry the weight of official history yet are contested on arrival, even before. Their authors are prosecutors and lawmakers, so the texts can veer from dense to prosaic to dramatic. The documents identify possible crimes and other misdeeds at the highest level, yet their political implications tend to overpower all else.

Robert S. Mueller’s report on Russian interference in the 2016 election — which he delivered to Attorney General William P. Barr on Friday — does not just complete two years of investigation, indictment, prosecution, and, of course, nonstop speculation and anticipation. It will also take its place alongside works on presidential scandals past. And Mueller will join the ranks of Sam Ervin, Archibald Cox, Leon Jaworski, Lawrence Walsh and Kenneth Starr.