( CNN) The last time someone used the Oval Office to execute a personal vendetta, it was dubbed the Saturday Night Massacre.

No one actually died in the scandal over Richard Nixon's firing of the special attorney looking into the Watergate recordings, but the blow to our conception of American democracy was devastating. Nixon's behavior challenged our sense of ego as a nation committed to the rule of statute, shook our faith in political leaders, and tarnished the global image of the United States as a model democracy.