“[T]here are some people who wish us to enact laws which would seriously damage the right of free speech and which could be used not only against subversive groups but against other groups engaged in political or other activities which were not generally popular. Such measures would not only infringe on the Bill of Rights and the basic liberties of our people; they would also undermine the very internal security they seek to protect.

Laws forbidding dissent do not prevent subversive activities; they merely drive them into more secret and more dangerous channels. Police states are not secure; their history is marked by successive purges, and growing concentration camps, as their governments strike out blindly in fear of violent revolt. Once a government is committed to the principle of silencing the voice of opposition, it has only one way to go, and that is down the path of increasingly repressive measures, until it becomes a source of terror to all its citizens and creates a country where everyone lives in fear.

We must, therefore, be on our guard against extremists who urge us to adopt police state measures. Such persons advocate breaking down the guarantees of the Bill of Rights in order to get at the communists. They forget that if the Bill of Rights were to be broken down, all groups, even the most conservative, would be in danger from the arbitrary power of government.”

— Harry S. Truman, Special Message to the Congress on the Internal Security of the United States, August 8, 1950

Presidential portrait of Harry Truman, by Greta Kempton, 1945