The California teachers who lost their challenge to “fair share” union fees to a 4-4 split in the U.S. Supreme Court asked the justices on Friday to take the rare step of rehearing their case.

“We can’t leave this issue for another time,” said Terry Pell, the president of the Center for Individual Rights, the public interest law firm that brought Friedrichs v. California Teachers Association on behalf of the nonunion teachers. “The court has already agreed to decide this case and it should hold the case until it can issue a definitive decision. A tie is simply not good enough when it comes to fundamental issues like the First Amendment.”