Forty years ago, President Richard M. Nixon announced that he would resign, effective the next day.

At the time, aside from a tiny minority of dead-enders and a few desultory congressional Republicans, an exhausted nation had arrived at a consensus that Nixon had to go. Politics had become too toxic, distrust of government too profound, and — most of all — the seriousness of the president's crimes couldn't be ignored.

Judicial sanction wasn't in Nixon's future — President Gerald Ford's controversial pardon ensured that — but the ultimate political punishment, impeachment, seemed like the absolute minimum sanction in order to send the message that no man, no matter how powerful, was above the law. Nixon's resignation, Ford assured Americans and the media agreed, proved that the system works.