The House is on fire. And with each passing day, Donald Trump defiles the office of the president. If only past defrocked presidents could provide a roadmap for this firestorm. Andrew Johnson fought impeachment vigorously and survived removal, but never won reelection. Richard Nixon got in the way of justice, but eventually bowed to the rule of law, accepting his asterisk in the annals of history and resigning before certain removal. Bill Clinton expressed contrition, went on to complete his presidency with high approval ratings and has remained a popular former president. If you care about democracy, the rule of...