New York Times

WASHINGTON — Supreme Court justices like to say that they have no agenda. Cases come to them unbidden. They decide the ones that need deciding.

The reality is more complicated. The justices sometimes use their opinions to send messages about the kinds of cases they would like to hear.

Signals sent in the term that just ended included one from Justice Anthony M. Kennedy, who asked for a case about solitary confinement, and another from Justices Stephen G. Breyer and Ruth Bader Ginsburg, who asked to consider the constitutionality of the death penalty.

The next term, which starts in October, will feature three cases brought at least partly in response to similar invitations.

One of them, a grave threat to public-sector unions, is a reaction to a 2012 majority opinion from Justice Samuel A. Alito Jr. In making a minor adjustment to how public unions must issue notifications about their political spending, Justice Alito digressed to raise questions about the constitutionality of requiring workers who are not members of public unions to pay fees for the unions’ work on their behalf.

“We do not revisit today whether the court’s former cases have given adequate recognition to the critical First Amendment rights at stake,” Justice Alito wrote.

Justice Sonia Sotomayor saw what was going on. “To cast serious doubt on longstanding precedent,” she wrote in a concurrence, “is a step we historically take only with the greatest caution and reticence. To do so, as the majority does, on our own invitation and without adversarial presentation is both unfair and unwise.”

Michael A. Carvin, a leading conservative lawyer, also saw what was going on. He and the Center for Individual Rights, a libertarian group, promptly filed the challenge Justice Alito had sketched out. Indeed, Mr. Carvin asked the lower courts to rule against his clients, a Christian education group and 10 California teachers, so they could high-tail it to the Supreme Court.

Last year, Justice Alito wrote a second majority opinion attacking the central precedent in the area, a 1975 decision called Abood v. Detroit Board of Education. But the majority in the new case, Harris v. Quinn, stopped short of overruling Abood.

By now everyone saw what was going on. “Readers of today’s decision will know that Abood does not rank on the majority’s top-ten list of favorite precedents — and that the majority could not restrain itself from saying (and saying and saying) so,” Justice Elena Kagan wrote in dissent.

Last week, the court agreed to hear Mr. Carvin’s case, Friedrichs v. California Education Association, No. 14-915, and it may soon complete the project Justice Alito began in 2012, that of overruling Abood.

Other projects have taken longer.

In 2001, Justice Clarence Thomas unsuccessfully urged the Supreme Court to decide just what the principle of “one person one vote” means.

The court has never said whether voting districts should have the same number of people or the same number of eligible voters. Most places count everybody.

Counting all people increases the voting power of areas with large numbers of residents who cannot vote, including immigrants who are there legally but are not citizens, unauthorized immigrants, children and people disenfranchised for having committed felonies. Those places tend to be urban and to vote Democratic.

“It behooves us to address this question as soon as possible,” Justice Thomas wrote in 2001.

In 2013 and again this year, the Project on Fair Representation, a small conservative advocacy group, asked the court to consider the issue. This time around, in Evenwel v. Abbott, No. 14-940, the court agreed.

The group, led by Edward Blum, a former stockbroker, is also behind the third major case on the next term’s docket, a challenge to the race-conscious admissions program at the University of Texas at Austin. In 2013, in a 7-to-1 compromise decision, the majority sent the case back to an appeals court, instructing it to take a more careful look at the admissions program.

Justice Breyer’s reaction was that of a man who had just dodged a bullet. “Phew,” he said in remarks in Aspen, Colo., that summer.

Justice Ginsburg took another approach, issuing the lone dissent. There was no need for further proceedings, she said, and no good would come from them. “I would not return this case for a second look,” she wrote.

Instead, she said, she would have upheld the Texas program under a 2003 decision that allowed the use of race as one factor of many in admissions decisions. Writing for the majority in that 5-to-4 ruling, Justice Sandra Day O’Connor said, “We expect that 25 years from now, the use of racial preferences will no longer be necessary.”

The dissenting justices in 2003 said they welcomed fresh challenges in the meantime. “The Constitution means the same thing today as it will in 300 months,” Justice Thomas wrote.

Last July, the appeals court again said the Texas program was constitutional. Mr. Blum’s group returned to the Supreme Court and asked for a do-over in the case, Fisher v. University of Texas, No. 14-981

Last week, the court agreed to hear that case, too.

These three marquee cases on the court’s docket next term — on public unions, voting and affirmative action — have a lot in common. They are creations of legal entrepreneurs. And they are reactions to signals from justices who have done more than wait for cases to arrive at their courthouse.