Smith Act, or Alien Registration Act of 1940, makes it a crime to advocate the violent overthrow of the United States government or to belong knowingly to a group advocating it. In 1951, the Supreme Court upheld the act in the case of 11 convicted leaders of the Communist Party. But in 1957, the court ruled that teaching Communism or other revolutionary theories was not, in itself, grounds for conviction. Proof was required that the defendant had urged direct action to overthrow the government.
In 1961, the Supreme Court again upheld the conviction of a member of the Communist Party under the act. The court maintained that in this case the person had been an active member of the Communist Party and had intended to overthrow the government of the United States.
