More than 40 years ago, the Supreme Court gave this arrangement its constitutional blessing. The justices set out a middle position in the case of the case of Abood vs. Detroit Board of Education. They said public employees have a free-speech right to opt out of paying the full dues to a union if some of the money is spent for political contributions or lobbying. However, the court said, they may be required to pay a lesser fee to support the union’s workplace activities. Otherwise, “free riders” could benefit from a better contract, but pay nothing.