Truly malignant ideas crop up in a democracy with the frequency of toadstools after a summer rain storm. Most of these ideas are dismissed by the great majority of citizens after public debate in one fashion or another. Some of the ideas hang on despite evidence to the contrary (sorry Texas was readmitted to the Union and the Income Tax was ratified by the requisite number of states) but attract no real following. Truly pernicious ideas, however, seem benign at first glance but in truth strike at the heart of our system of government. The “Oath Keeper” movement is one...