After enduring three days of outlandish claims and grievances about American life at the Charlotte convention, I wrote that “something shocking is happening to the Democratic Party.” Five weeks later, I must amend the observation. The soul-sapping transformation is no longer “happening.” It is complete. The Democratic Party has lost its mind and its way. Its political philosophy of inclusion and progress has been consumed by virulent strains of anger, dishonesty and intolerance. Its leaders don’t just want to win an election; they want to silence any American who disagrees with them. Consider the latest evidence. The White House, on...