In the 1964 case, Veterans of the Abraham Lincoln Brigade v. Subversive Activities Control Board, the United States Supreme Court upheld a ruling by the Subversive Activities Control Board that required members of certain organizations to register with the government. The Veterans of Abraham Lincoln Brigade was an organization made up primarily of Americans who had fought against fascism in Spain during its civil war in 1936-39. They were ordered to register as a "Communist-action" group under provisions set forth by Internal Security Act (ISA) due to their alleged ties with Communist Party USA and other communist groups worldwide. The court ruled that this requirement did not violate First Amendment rights because it only required registration and disclosure rather than prohibiting or punishing any particular speech or association directly.

In the dissenting opinion for Veterans of the Abraham Lincoln Brigade v. Subversive Activities Control Board, Justice William O. Douglas argued that the majority's decision violated First Amendment rights to freedom of speech and association. He contended that it was unconstitutional to label an organization as "subversive" based on its political beliefs or affiliations, even if those beliefs were unpopular or controversial. Furthermore, he criticized the majority for allowing guilt by association and warned against government overreach in regulating political activity. According to him, such actions could lead down a slippery slope towards totalitarianism where any dissent is suppressed under law.