The justices unanimously reversed a Washington State Supreme Court decision that found unions could use agency fees as they wished unless non-members objected.
Many states have agency shop provisions that require all public employees where a union exists to pay dues. Justice Antonin Scalia said that Washington's "modest limitation" on the use of those fees does not violate the First Amendment since the state could have barred the union from using non-member fees for any lobbying or political activity.
"Unions have no constitutional right to the fees of non-member employees," Scalia said.
Instead, the court found, public employees who don't choose to belong to a union have a free speech right to withhold the use of their money.