Public employee unions suffered a major defeat at the U.S. Supreme Court on Monday, with worse probably to come soon.

The court's 5-4 decision will in the short run undercut the financing for some public employee unions by allowing people who don't join the union and don't pay any fees to get the same benefits as those who do pay union dues.

In 1977 the Supreme Court ruled that when employees vote to unionize, those who do not join the union still have to pay what are called "fair share" fees — that is, they have to pay for the negotiation of the contract they benefit from, and cannot free-ride on members' dues. In recent years, some conservatives on the Supreme Court have openly suggested it is time to overrule that decision. And on Monday the court took its first steps toward doing just that.

The specifics of the case were these: Ten years ago, 28,000 home health workers who care for adults with disabilities voted to approve a union. Since then, hourly wages have nearly doubled; the workers now receive regular training and have health insurance themselves.

The state of Illinois is happy: It says rapid turnover among workers has been stopped, the workforce has been stabilized and professionalized, and the government has saved more than $600 million by keeping adults with disabilities in their homes instead of in institutions.

But some workers object to paying anything to the union, contending such payments violate their First Amendment right of free speech.

On Monday the court ruled for those objectors, but dodged a First Amendment ruling on all public employee unions. Instead, the conservative majority said the home health care workers in Illinois are only partial public employees, since they are hired and fired by the patients. Therefore, the majority said, there is no requirement that those who do not join the union pay fair share fees.

That is not, however, where the decision ended. Writing for the majority, Justice Samuel Alito said the 1977 decision is based on "questionable foundations." It drew a line between permissible fees paid by nonmembers for contract negotiation and grievance procedures on the one hand, and impermissible fees for political or ideological purposes on the other. Alito said that in the public sector, however, public employee unions are essentially lobbyists for more money and more employees, whereas in the private sector the marketplace imposes its own limits.

Rebutting Alito for the dissents, Justice Elena Kagan asked: "Does the majority think that public employees are immune from basic principles of economics" too? After all, she said, unless everyone who benefits from a union contract has to pay their fair share, a union will be unable to attract sufficient money to support its functions." Taken to its logical conclusion, she seemed to say public employee unions will cease to exist.

"The handwriting is indeed on the wall," said former National Labor Relations Board chair William B. Gould IV. "And the public sector unions face a daunting task in fending off future adverse rulings."

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