The Supreme Court announced on Monday that it will hear Fulton v. City of Philadelphia, a hugely consequential case that could fundamentally change the rules governing when people with religious objections to a law may ignore that law.

Fulton asks whether religious organizations that contract with Philadelphia to help place foster children in homes have a First Amendment right to discriminate against same-sex couples. It is also the first case the Supreme Court will hear where a religious group claims the right to violate a ban on discrimination since Justice Brett Kavanaugh’s confirmation gave reliably conservative Republicans a majority on the Supreme Court.

The plaintiffs in Fulton include Catholic Social Services (CSS), an organization that used to contract with the city to help find foster placements for children but that effectively lost that contract after it refused to comply with the ban on discrimination. CSS claims it has a First Amendment right to continue to do business with the city even if it refuses to comply with the city’s anti-discrimination rules.

Fulton is a significant escalation from most of the Supreme Court’s previous cases asking when religious people may seek an exemption from the law. In Masterpiece Cakeshop v. Colorado Civil Rights Commission (2018), for example, the Supreme Court considered whether the law could prevent a private business owner from discriminating against a same-sex couple (the Court ruled in favor of the business owner, but on narrow grounds).

Fulton, by contrast, is a case about government services. The city of Philadelphia decided to contract with private organizations to help it provide a public service — placement of children in foster homes. If the city chose to provide this service entirely in house, it could certainly refuse to discriminate against same-sex couples. The question in Fulton is whether the city loses much of its power to control its own public services when it contracts some of those services to religious entities.

A decision for the plaintiffs in Fulton, moreover, could have implications that stretch well beyond foster care. The Fulton case involves an especially sympathetic plaintiff: a Catholic organization that helps vulnerable children find homes. But if the Supreme Court rules in favor of that plaintiff, it could potentially establish that a wide range of government contractors, from social service providers to military contractors, may discriminate if the company’s owners claim a religious justification for that discrimination.

On top of all that, the Fulton plaintiffs ask the Supreme Court to reconsider a seminal 1990 decision limiting when religious objectors may refuse to follow the law. Fulton could also lead to a massive expansion of the Court’s decision in Burwell v. Hobby Lobby (2014), which held, for the first time, that religious objectors may sometimes use those objections to limit the rights of third parties.

In other words, Fulton could be the next big blow in the fight between religious conservatives who seek broad legal exemptions, and laws seeking to ban conduct such as anti-LGBTQ discrimination without exception.

A brief history of the First Amendment’s free exercise clause

The First Amendment prevents the government from “prohibiting the free exercise” of religion. In Sherbert v. Verner (1963), the Supreme Court established that this free exercise clause prohibits the government from enforcing laws that impose a “substantial infringement” on someone’s religious beliefs unless the government’s reasons for doing so are supported by a “compelling state interest.”

Those last three words — “compelling state interest” — will be familiar to anyone who has studied American constitutional law. The Supreme Court also requires laws that discriminate on the basis of race to overcome a “compelling interest” test. When the Court uses the words “compelling interest,” it typically signals that the Constitution applies the highest possible safeguards against a particular kind of government action. Most laws that are subjected to a “compelling interest” analysis are struck down.

Yet something odd happened after the Supreme Court decided Sherbert. While the courts claimed they were applying the same “compelling interest” test in cases involving race discrimination and in cases involving religious objectors, the numbers do not bear this out. A 1992 study by James E. Ryan, now the president of the University of Virginia, found that federal courts of appeals heard 97 free exercise cases applying the “compelling interest” test between 1980 and 1990, and those courts rejected 85 of these cases.

Subsequent research by UCLA law professor Adam Winkler showed that this pattern continued into the next decade. Between 1990 and 2003, Winkler found, federal courts applying the compelling interest test upheld only 22 percent of free speech restrictions and 27 percent of laws that engaged in discrimination — but they upheld 59 percent of “religious liberty burdens.” These data indicate that “religious liberty” plaintiffs are far less likely to prevail than other parties who challenge the government’s actions under a “compelling interest” test.

A likely explanation for this disparity is that courts found the notion that any religious person could be exempt from nearly any law unworkable, so they were reluctant to read the free exercise clause too expansively. By 1990, this sense, that applying a strong “compelling interest” standard to religion cases is unworkable, won a majority of the votes on the Supreme Court.

“To make an individual’s obligation to obey such a law contingent upon the law’s coincidence with his religious beliefs, except where the State’s interest is ‘compelling,’” Justice Antonin Scalia wrote for the Court in Employment Division v. Smith (1990), is “permitting him, by virtue of his beliefs, ‘to become a law unto himself.’” Such an outcome, according to Scalia, “contradicts both constitutional tradition and common sense.”

Instead, Scalia wrote, religious people have to follow the same “neutral law[s] of general applicability” that everyone else must follow. The law may not single out particular religious groups for inferior treatment. But so long as a law treats people of all religious beliefs exactly the same, the law is constitutional. Philadelphia may ban anti-LGBTQ discrimination so long as the ban applies equally to religious people and nonreligious people alike.

Smith, however, was not a beloved decision. In 1993, Congress enacted the Religious Freedom Restoration Act (RFRA) to “restore the compelling interest test as set forth in Sherbert” and in a similar Supreme Court decision. RFRA, it should be noted, applies only to federal laws that burden religious objectors. Smith remains good law when a state is accused of violating the free exercise clause.

Moreover, as Winkler’s research suggests, RFRA did not cause the courts to fundamentally rethink their religion decisions — at least not right away. Religious liberty plaintiffs were more likely to win their cases after RFRA than they were before it was enacted, but most of these plaintiffs still lost. Most notably, the courts typically hewed to the view that a religious objection may not be used to undercut the rights of a third party.

But all of that changed with the Court’s 2014 decision in Hobby Lobby. Hobby Lobby held that certain companies, whose owners object to some forms of birth control on religious grounds, may refuse to obey a federal rule requiring them to provide birth control coverage to their employees. In effect, that meant that the “religious liberty” rights of the business owners trumped the right of the workers to have birth control coverage.

The Court’s decision in Hobby Lobby, moreover, suggests that courts should apply the same “compelling interest” test in RFRA cases that it applies in race cases. So courts must treat federal laws that substantially burden religious exercise with the same high amount of skepticism they give to laws about racial discrimination.

As Ryan and Winkler’s studies show, that’s not how courts have behaved in the past.

What the Fulton plaintiffs want

The Fulton plaintiffs make several legal claims, but one of their most aggressive claims is that the Supreme Court should reconsider Smith.

Recall that Hobby Lobby was an RFRA case, which means its expansion of “religious liberty” applies only to the federal government. If the Supreme Court overrules Smith, that would mean that state laws that trigger religious objections would also be subject to a strict compelling interest test. We would move closer to the world that Scalia warned of, where a religious individual might “become a law unto himself.”

Additionally, the Fulton plaintiffs claim that the city may not condition “benefits on the surrender of constitutional rights” — and thus the city may not screen its contractors to exclude businesses that want to discriminate on religious grounds. As noted above, a decision ruling in the plaintiffs’ favor on such grounds could have major implications for many government contracts.

It is very likely, moreover, that the Court will use Fulton to significantly expand the rights of religious objectors. Shortly after Scalia died in 2016, Justice Samuel Alito penned an opinion endorsing an expansion of religious objectors’ rights, and that opinion was joined by Chief Justice John Roberts and Justice Clarence Thomas.

Those three justices are now joined by two conservative Trump appointees, Kavanaugh and Justice Neil Gorsuch. While it is unclear just how far the Court will go in Fulton, it is now likely that there are five votes to hold that organizations like CSS may discriminate against same-sex couples.