In the case of Kahn et al. v. Anderson, Warden of the United States Penitentiary at Leavenworth, Kansas (1920), the petitioners were convicted for violating a federal law that prohibited false statements or representations to influence or impede military operations during World War I. The defendants argued that their convictions violated their First Amendment rights to free speech and assembly as they had only been expressing opposition to American involvement in WWI through speeches and pamphlets. However, the Supreme Court upheld their conviction stating that while freedom of speech is protected under the Constitution, it does not extend to words used in such circumstances and are of such nature as to create a clear and present danger that they will bring about substantive evils which Congress has a right to prevent.

In the dissenting opinion for Kahn et al. v. Anderson, Justice Louis Brandeis argued that the majority's decision was a departure from established legal principles and an overreach of federal authority. He contended that Congress did not have the power to make it a crime to conspire to teach or advocate overthrowing state governments by force or violence, as this fell under states' rights issues rather than federal jurisdiction. Furthermore, he believed that such laws violated First Amendment protections of free speech and assembly unless there was clear evidence of imminent danger resulting from these activities - something which he felt had not been demonstrated in this case.