This issue was previously before the Supreme Court in a 1977 case titled Abood v. Detroit Board of Education. In that decision, the Supreme Court made a distinction between two kinds of compelled payments. It held that workers need not pay for the political activities of unions, like campaign spending, as that would violate their First Amendment rights. However, the Supreme Court also concluded that it is constitutional to require nonmembers to help pay for the union's collective bargaining efforts to prevent freeloading and to ensure "labor peace." Interestingly, Mark Janus conceded in both the district court and before the Seventh Circuit that the Abood decision was still good law, but argued that the Supreme Court might reverse that decision. Both the district court and the Seventh Circuit dismissed Mr. Janus's claims.
The same question was before the Supreme Court last year in a case titled Friedrichs v. California Teachers Association. Following the death of Justice Scalia, the Supreme Court issued a 4-4 decision that did not result in the reversal of the Abood opinion. Given the appointment of conservative Justice Gorsuch to the Supreme Court during the intervening period, however, the result in the Janus case could be different, with Justice Gorsuch supplying the fifth vote against the unions. A ruling allowing workers to refuse to pay the fees would be the culmination of a decades-long campaign by conservative groups aimed at weakening unions that represent public employees. That ruling would also deal a serious blow to the unions, which would lose a significant source of revenue from the mandatory union dues payments.