Sixty years ago today, Attorney General Robert Kennedy granted J. Edgar Hoover and his FBI a long-awaited gift: permission to conduct electronic surveillance on the Rev. Martin Luther King Jr. The bureau and federal legislators have since declared the campaign against King as a cardinal sin in national security. Yet, the FBI and America still have not learned from this history. The FBI labeled King a “communist threat.” But they knew better. The FBI had no facts to substantiate its conclusion, but it did not matter. “Facts by themselves are not too meaningful,” the FBI’s Domestic Intelligence Division noted. “They...