Seventy-five years ago this June, the United States Supreme Court corrected its own grave moral and legal error and ruled that the government could not compel Jehovah's Witnesses to salute the flag and take the Pledge of Allegiance at school. Justice Jackson's stirring words were a watershed moment in American recognition of individual liberty in the face of government demands for uniformity: If there is any fixed star in our constitutional constellation, it is that no official, high or petty, can prescribe what shall be orthodox in politics, nationalism, religion, or other matters of...