New York Times

WASHINGTON — The Supreme Court will hear arguments on Monday in a case that is making the labor movement nervous. Here is a look at the legal issues in the case and the possible consequences of a ruling, which is expected by June.

Q. Who are the plaintiffs, and what do they want?

A. Ten California teachers who have chosen not to become members of the union that represents them sued over a state law that nonetheless required them to pay a fee for their share of the union’s collective bargaining expenses. Calling the requirement “the largest regime of compelled political speech in the nation,” they say it violates the First Amendment.

Q. What do the unions say?

A. The unions respond that collective bargaining is not a political activity and that the plaintiffs are seeking to take a free ride on the union’s work in obtaining higher wages and better benefits.

Q. Why is the case important?

A. A decision in favor of the challengers would allow millions of government workers in more than 20 states to opt out of paying for collective bargaining, depriving unions of vast sums of money and making them less effective.

Q. Has the Supreme Court addressed this issue before?

A. Yes. In 1977, in Abood v. Detroit Board of Education, the court said requiring nonmembers to pay for collective bargaining was constitutional. (In another part of the decision, the court said forcing nonmembers to pay for the union’s political work violated the First Amendment.) The California plaintiffs are asking the Supreme Court to overrule the Abood decision.

Q. Is there reason to think the Supreme Court will rule for the plaintiffs?

A. Yes. In decisions in 2012 and 2014, a majority of the justices indicated that they had grave doubts about the Abood decision, seeming to invite a major challenge to the precedent.

Q. Who is behind the new case?

A. The case, Friedrichs v. California Teachers Association, No. 14-915, was organized by the Center for Individual Rights, a libertarian group. The plaintiffs’ lead lawyer, Michael A. Carvin, represented the challengers last year in King v. Burwell, a failed attempt to strike down nationwide tax subsidies under the Affordable Care Act. Mr. Carvin pursued an unusual litigation strategy in the teachers’ case, asking lower courts to rule against his clients so he could speed the case to the Supreme Court.

Q. Will the case turn on Justice Anthony M. Kennedy’s vote?

A. Probably not. The last time the issue was argued before the court, in 2014, the lawyer for the union received hostile questions from Justice Kennedy and sympathetic ones from an unlikely source, Justice Antonin Scalia.

“What our cases say,” Justice Scalia said in 2014, is that “you can be compelled not to be a free rider, to pay for those items of bargaining that benefit you as well as everybody else.” But when the decision landed on the last day of the term that June, Justice Scalia joined without comment a majority opinion in large part devoted to a biting critique of the Abood decision.