In the 1973 case Lehman v. City of Shaker Heights, Harry J. Lehman challenged a city policy that prohibited political advertisements on public transportation vehicles. The Supreme Court ruled in favor of the City of Shaker Heights, stating that it was within its rights to refuse such advertising as part of its commercial venture and this did not infrally upon First Amendment rights. The court held that there was no discrimination against viewpoints since all political advertising was banned uniformly and therefore, it didn't violate free speech principles under the First Amendment. This decision established precedent for similar cases involving restrictions on advertisement in public spaces.

In the dissenting opinion for Lehman v. City of Shaker Heights, Justice Douglas argued that the First Amendment should protect political speech in public spaces, including advertising on public buses. He contended that a city cannot constitutionally select which types of protected speech to allow and which to prohibit based solely on its content. In his view, by allowing commercial advertisements but not political ones, the city was making an impermissible distinction between different types of free expression. Furthermore, he disagreed with the majority's assertion that bus riders are a "captive audience" who could be unduly influenced or annoyed by such ads; instead he believed they have every right to ignore them if they choose so. Therefore, according to Justice Douglas' dissenting opinion, banning political advertisements from public buses violated freedom of speech protections under the Constitution.