"Struggles to coerce uniformity of sentiment in support of some end thought essential to their time and country have been waged by many good as well as evil men. Nationalism is a relatively recent phenomenon but at other times and places the ends have been racial or territorial security, support of a dynasty or regime, and particular plans for saving soul. As first and moderate methods to attain unity have failed, those bent on its accomplishment must resort to an ever-increasing severity. As governmental pressure toward unity becomes greater, so strife becomes more bitter as to whose unity it shall be. Probably no deeper division of our people could proceed from any provocation than from finding it necessary to choose what doctrine and whose program public educational officials shall compel youth to unite in embracing. Ultimate futility of such attempts to compel coherence is the lesson of every such effort from the Roman drive to stamp out Christianity as a disturber of its pagan unity, the Inquisition, as a means to religious and dynastic unity, the Siberian exiles as a means to Russian unity, down to the fast failing efforts of our present totalitarian enemies. Those who begin coercive elimination of dissent soon find themselves exterminating dissenters. Compulsory unification of opinion achieves only the unanimity of the graveyard.
"It seems trite but necessary to say that the First Amendment to our Constitution was designed to avoid these ends by avoiding these beginnings. There is no mysticism in the American concept of the State or of the nature or origin of its authority. We set up government by consent of the governed, and the Bill of Rights denies those in power any legal opportunity to coerce that consent. Authority here is to be controlled by public opinion, not public opinion by authority."
-- U.S. Supreme Court Justice Robert H. Jackson, West Virginia Board of Education v. Barnette, 1943
[My suggested bumper-sticker-sized soundbite for folks averse to chewing long paragraphs first thing in the morning: "Those who begin coercive elimination of dissent soon find themselves exterminating dissenters. Compulsory unification of opinion achieves only the unanimity of the graveyard."]