In the case of Clark, Secretary of the Interior, et al. v. Community for Creative Non-Violence et al., 1983, the U.S Supreme Court ruled in favor of Clark and his co-defendants. The dispute arose when a group known as Community for Creative Non-Violence (CCNV) was denied a permit to conduct an overnight sleep-in demonstration at Lafayette Park and the Mall by National Park Service due to regulations prohibiting camping on these sites. CCNV argued that this denial infringed upon their First Amendment rights to freedom of speech and expression. However, the court held that while public spaces are traditionally used for public assembly and communication purposes, government entities can impose restrictions if they are content-neutral and serve significant governmental interests such as preservation of park resources which is considered substantial enough interest here.

In the dissenting opinion for Clark v. Community for Creative Non-Violence, Justice Thurgood Marshall argued that the National Park Service's regulation banning camping in certain parks violated the First Amendment rights of demonstrators who were using sleep as a form of symbolic speech to protest homelessness. He believed that sleeping was an integral part of their message and thus should be protected under free speech laws. Furthermore, he disagreed with the majority's view that there were ample alternative channels for communication available to protesters; instead, he felt these alternatives would not convey their message as effectively or poignantly. Lastly, Justice Marshall questioned whether maintaining park aesthetics and avoiding potential damage truly justified infringing upon constitutional rights given other potentially less restrictive means to achieve those ends.