Inaugurations of a U.S. president often reverberate with religious overtones. The ceremonies blend the sacred and the secular, infusing the launch of a new political era with the weight of a religious experience. One presidential historian claimed that the rituals and ceremonies of inauguration day bore all the “solemnity of a sacrament.” Into this civic religion, into this attempt of government — and those who see it as a savior — to take for itself religious meaning and fervor, good...