October 20 marked the 40th anniversary of one of the most riveting political events in American history: the Saturday Night Massacre. In one dramatic convulsion, national attention focused on President Richard Nixon’s refusal to produce tape recordings subpoenaed by the grand jury investigating Watergate. So important was it to him for the tapes to remain secret that he was willing to sacrifice his newly minted attorney general to keep from divulging it.

Prior to the Saturday Night Massacre, even with the televised Senate hearings in which former White House counsel John Dean gave damaging testimony implicating the president and high administration and campaign officials in a wide-ranging conspiracy to obstruct justice, it seemed that most Americans were willing to give Nixon and his senior aides the benefit of the doubt. Nixon and his aides refuted Dean’s claims and said they had no knowledge of, much less involvement in, illegal activity.