 In 1958 , the leader of the North Carolina branch of the CPUSA , Junius Scales , became the final CPUSA member convicted under the Smith Act , and the only one convicted after the Yates decision . Prosecutors pursued Scales ' case because he specifically advocated violent political action and gave demonstrations of martial arts skills . Scales was accused of violating the membership clause of the Smith Act , not the clause prohibiting advocacy of violence against the government . In his appeal to the Supreme Court , Scales contended that the 1950 McCarran Internal Security Act rendered the Smith Act 's membership clause ineffective , because the McCarran Act explicitly stated that membership in a communist party does not constitute a per se violation of any criminal statute . In 1961 , the Supreme Court , in a 5 – 4 decision , upheld Scales ' conviction , finding that the Smith Act membership clause was not obviated by the McCarran Act , because the Smith Act required prosecutors to prove first , that there was direct advocacy of violence ; and second , that the defendant 's membership was substantial and active , not merely passive or technical . Two Justices of the Supreme Court who had supported the Yates decision in 1957 , Harlan and Frankfurter , voted to uphold Scales ' conviction . 
