The U.S. Supreme Court case Yates v. United States in 1957 dealt with the issue of free speech and its limits under the Smith Act, a law that made it illegal to advocate for the violent overthrow of government. The defendants were fourteen leaders of the Communist Party USA who had been convicted under this act for their political beliefs and activities. However, they argued that they only advocated for change through peaceful means, not violence or forceful overthrow as charged by prosecution. In a 6-1 decision, the court ruled in favor of Yates and her co-defendants stating that while it was constitutional to punish those advocating for immediate violent action against government (clear and present danger), mere advocacy or teaching abstract doctrine did not constitute such threat unless aimed at inciting imminent lawless action. Therefore, since there was no evidence showing these individuals urged others to take up arms immediately against state authority but merely discussed Marxist-Leninist theory which included conceptually an eventual need for revolution; their conviction could not stand. This ruling significantly narrowed down interpretation/application scope of Smith Act thereby protecting freedom of speech even when ideas expressed are unpopular or radical.

In the dissenting opinion for Yates v. United States, Justice Clark argued that the majority's interpretation of the Smith Act was too narrow and inconsistent with its original intent. He believed that advocating for violent overthrow of government should be considered a punishable offense under this act, regardless if it is immediate or in an indefinite future. Furthermore, he contended that Congress intended to criminalize both advocacy and teaching of such doctrine when they passed this law. The distinction between abstract theory and active incitement made by the majority was seen as artificial by him because even theoretical discussions can lead to actual violence eventually. Moreover, he expressed concern about potential threats posed by Communist Party members who were defendants in this case due to their allegiance to a foreign power known for using forceful means against democratic institutions.