In the case of Marchioro et al. v. Chaney et al., 1978, the U.S Supreme Court ruled in favor of Washington state's law that limited political parties to appointing only one poll watcher per polling place during elections. The appellants, members and officers of a local Democratic Party committee, argued that this restriction violated their First Amendment rights by limiting their ability to gather information about voter eligibility and potential election fraud. However, the court disagreed with this argument stating that while gathering such information is protected under the First Amendment, it does not guarantee an unrestricted right for political parties to deploy multiple poll watchers at each polling station. The court held that states have significant interests in preserving order and preventing confusion or intimidation at polling places which justified these restrictions on poll watching activities.

In the dissenting opinion for Marchioro et al. v. Chaney et al., Justice Brennan, joined by Justice Marshall, argued that Washington State's law requiring a political party to have precinct committee officers in at least 40% of the state's precincts was unconstitutional. They believed it violated the First and Fourteenth Amendments as it imposed an unnecessary burden on minor parties' freedom of association rights without any compelling state interest justifying such infringement. The justices felt that this requirement could potentially exclude smaller or newer political parties from participating in elections, thereby limiting voters' choices and stifering political diversity - both crucial elements of a healthy democracy. Furthermore, they disagreed with the majority’s view that this rule helped ensure broad-based support; instead suggesting alternative methods like petition signatures could serve similar purposes without infringing upon constitutional rights.