The end of prosecutions
The indictments and trials ended in 1957 as the result of a series of Supreme Court decisions. Yates v. United States ruled unconstitutional the convictions of numerous party leaders in a ruling that distinguished between advocacy of an idea for incitement and the teaching of an idea as a concept. The Court ruled 6-1 in Watkins v. United States that defendants could use the First Amendment as a defense against "abuses of the legislative process."Template:354 U.S. 178 (1957)
On June 5, 1961, the U.S. Supreme Court upheld by 5-4 the conviction of Junius Scales under the "membership clause" of the Smith Act. Scales began serving a six-year sentence on October 2, 1961. He was released after serving fifteen months when President John F. Kennedy commuted his sentence in 1962.