Jimmy Carter knew that one way to win the trust of the citizenry was to appeal to their moral vanity. He was elected president in 1976 promising "a government that is as good and honest and decent and competent and compassionate and as filled with love as are the American people." Donald Trump does not try to ingratiate himself by telling Americans how good they are. He does it by telling them it's commendable to be bad. His campaign is not so much a challenge to prevailing standards as a rejection of all standards. Other candidates fudge, exaggerate and mislead,...