4 June 1951
Supreme Court Upholds Smith Act
Passed in 1940, the Alien Registration Act—better known as the Smith Act—made it a crime to “knowingly or wilfully advocate, abet, advise, or teach the duty, necessity, desirability, or propriety of overthrowing the Government of the United States or of any State by force or violence.” Over the next several years it was used to prosecute a number of individuals suspected of publicly supporting communism or fascism. However, in 1949 eleven leaders of the Communist Party of the United States were charged under the Smith Act, with the prosecution arguing that they had conspired to “teach the principles of Marxism-Leninism.” In a trial that lasted nine months, all were found guilty. Ten of the defendants were sentenced to five years in prison, while the eleventh was sentenced to three. In addition, all of their defense attorneys were given prison sentences for contempt of court.

The defendants immediately appealed their case, claiming that the Smith Act was an unconstitutional infringement on the right of free speech. The case made it all the way to the Supreme Court, which in the decision Dennis v. United States (Eugene Dennis was leader of the Communist Party) upheld the convictions. In a 6-2 decision (Justices Hugo Black and William O. Douglas dissented), the Court ruled that there were limits on free speech, and that advocating the overthrow of the United States government represented a “clear and present danger.”

More prosecutions of leading American communists continued over the next several years. However, in 1957 the Supreme Court, in Yates v. United States, ruled that there was a difference between teaching Marxism as a concept—which was protected under the First Amendment—and inciting the actual overthrow of the United States. Prosecutions against communists therefore came to an end, although the Smith Act remains part of American law, and Dennis v. United States has never been overturned.

- “Communists are second to none in our devotion to our people and to our country”: Prosecution and Defense Statements, 1949 Trial of American Communist Party Leaders