Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

WASHINGTON — A closely divided U.S. Supreme Court took up a case Monday that's likely to deal a crippling blow to unions representing millions of the nation's public employees.

The justices will decide whether state government workers who choose not to join a union must still pay a share of union dues to cover the cost of negotiating contracts.

The court deadlocked 4-4 on the same issue two years ago in a case brought by a group of California teachers opposed to paying the dues. Since then, conservative Neil Gorsuch has joined the court, and he seems all but certain to provide the fifth vote opponents need to strike the fees down.

But with both sides in the case — and the other justices — eager to hear from Gorsuch, he said nothing during the hour-long argument Monday, declining to ask a single question.

Even so, it would be a considerable surprise if Gorsuch joined the court's liberals to provide a fifth vote in favor of the unions. Instead, the unions seemed headed for a big fall.

As for the other eight members of the court, the division appeared to be the same as it was when the court last heard the case.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Ruling against the union "drains it of resources that make it an equal partner in collective bargaining," Justice Ruth Bader Ginsburg said.

Justice Sonia Sotomayor told the lawyer challenging the fees, "You're basically arguing, do away with unions."

At stake is the financial health of public sector unions in the 22 states where they bargain for both members and nonmembers alike.

The court has long held that requiring nonunion members to pay the full amount of union dues would violate their right of free expression, forcing them to subsidize a union's political activities whether they agree with its goals or not.

But since 1977, the court has also said that nonunion employees can be required to pay a portion of union dues, known as agency fees, to cover the cost of collective bargaining and prevent "free riders" — workers who get the benefits of a union contract without paying anything for it.

The current challenge began with a lawsuit filed against a state union by Illinois Gov. Bruce Rauner, a Republican. He was eventually dropped from the litigation, but a state child support specialist, Mark Janus, is carrying on the fight.

"Nobody asked me if I wanted to pay these dues. I never got the opportunity to say no," Janus said, claiming that the dues requirement violates the freedom of association guaranteed by the First Amendment.

His lawyers told the court Monday that even the positions unions take in collective bargaining are essentially political, because the quality of public services is at stake.

Justice Anthony Kennedy agreed. "What we're talking about here," he said, "is compelled subsidization of a private party, a private party that expresses political views constantly."

Chief Justice John Roberts suggested that "the need to attract voluntary payments will make the unions more efficient, more effective, more attractive to a broader group of their employees."

But David Frederick, a Washington lawyer representing the Illinois union, told the court that agency fees are justified by the expense of contract negotiations. Unions would have less political influence, he said, if the court rules against them.

The court will decide the case by late June.