The dynamics of the latter can be seen by tracking one of the most powerful phenomena of the last century: the Red Scare(s). Anti-communist hysteria followed World War I and did not cease until the fall of the Soviet Union in 1991. One law epitomized the dynamics: The Alien Registration Act of 1940.
Most often called the Smith Act, after Congressman Howard Smith (D-Va.), the Alien Registration Act is a federal statute that required all adult non-U.S. residents to register with the Immigration and Naturalization Service; it also made it a crime to advocate the overthrow of any U.S. government, including a "State, Territory, District or Possession thereof, or the government of any political subdivision therein."
It said that anyone who "knowingly or willfully advocates, abets, advises, or teaches the duty, necessity, desirability, or propriety of overthrowing or destroying the government" was liable both to fines and imprisonment for a maximum of 20 years. The prohibited methods of advocacy were printing, publishing, editing, issuing, circulating, selling, distributing, or the public display of such advocacy. The Smith Act targeted anyone who "organizes or helps or attempts to organize any society, group, or assembly of persons" who encouraged the overthrow of "government by force or violence; or [who] becomes or is a member of, or affiliates with" such groups.