In a one-sentence statement in Friedrichs v. California Teachers Association, the Court said that “the judgment is affirmed by an equally divided Court.”

That decision will send the case back to lower courts to consider again and leaves in place the precedent that teachers and other public workers, in about half on the nation’s unions, need to pay fees to support unions, even if they don’t participate in them.

In the case, the Court was asked to determine whether requiring teachers to pay mandatory dues for union activities violates the First Amendment.

The concept of fair-share payments was previously upheld in Abood v. Detroit Board of Education. This system is a compromise between free-speech and labor advocates, in which a union’s non-consenting members are required to pay for only the most basic tasks of representation, such as negotiating contracts. Under Abood, employees do not have to subsidize the political activities of the union, as that would amount to forced speech.

California teacher Rebecca Friedrichs, supported by the Center for Individual Rights, argued that she should have no obligation to pay any union dues whatsoever, since any payment is still a violation of her First Amendment right to free speech.

Last year, in Harris v. Quinn,  the Court said home health care aides in Illinois didn’t have to pay union representation costs for a public workers’ union they didn’t belong to. But the Court also said the workers weren’t “full-fledged public employees,” upholding in principle the Abood decision that underpins the public union sector.

In 1977, the Court said in Abood that states could make workers contribute to public unions. In his majority Harris decision, Justice Samuel Alito was highly critical of the Abood precedent, but in the end, the Court’s conservative bloc decided to rule narrowly on the issue of the Illinois workers and leave bigger issues about public sector unions for another day