What case established the 'clear and present danger doctrine'?

The case that established the "clear and present danger doctrine" is Schenck v. United States (1919). In this landmark decision, the Supreme Court ruled that speech could be restricted if it presents a clear and present danger of causing significant harm that the government has a legitimate interest in preventing.

In the context of World War I, Charles Schenck was convicted for distributing pamphlets that urged resistance to the draft. Justice Oliver Wendell Holmes, Jr., in his opinion, famously stated that the right to free speech is not absolute and can be curtailed when it poses a significant threat to public safety or national security. This doctrine was pivotal in shaping how the First Amendment was interpreted regarding freedom of speech during times of crisis, suggesting that the government could limit speech that incited unlawful actions or posed a severe threat to society.

This decision set a precedent for future cases that addressed the limits of free speech, prompting ongoing discussions about the balance between individual rights and societal safety. While later cases, such as Brandenburg v. Ohio, refined the standard for when speech could be limited, establishing a more protective framework for free speech, it was Schenck that originally articulated this vital legal concept.