The Supreme Court held 9-0 Thursday in Fulton v. Philadelphia that Catholic Social Services is exempt from municipal laws that would have required it to place foster children with gay couples. Yet despite this result, the case isn’t the win that religious liberty advocates wanted.

The ruling was unanimous, but divisions appeared in the justices’ separate concurrences. The ruling opinion, written by Chief Justice John Roberts, strained mightily to preserve a key precedent that says the Constitution doesn’t guarantee a religious liberty exemption from laws that are neutral and generally applicable. That precedent, Employment Division v. Smith, survived the ax this time but is still in grave jeopardy, as evidenced by a concurrence from Justice Amy Coney Barrett that contemplated ways to overrule it.

The 1990 Smith precedent, written by Justice Antonin Scalia, has long been targeted by religious liberty advocates. It dates back to an earlier time when conservatives disliked the idea of exemptions for religious groups from neutral, generally applicable laws while liberals eagerly embraced it.

The debate in Smith was about peyote use in American Indian religious ceremonies. Since then, the politics of religious exemptions have flipped, with LGBTQ rights, abortion and birth control dominating the discussion of religious exemptions.

Justices Samuel Alito and Neil Gorsuch have the Smith precedent squarely in their sights. Justice Clarence Thomas is also ready to reverse it. Religious liberty advocates saw a golden opportunity to get Justices Brett Kavanaugh and Barrett to provide the fourth and fifth votes to overturn Smith.

Why didn’t they? On its facts, the case seemed to belong rather obviously to the Smith paradigm. The Philadelphia law that bars discrimination against gay couples is neutral in the sense that it doesn’t target any religious group. And it fits into any ordinary interpretation of the phrase “generally applicable,” because it applies to everyone.

According to the Smith rule, if a law is neutral and generally applicable, there is no constitutional right to a religious liberty exemption from it. Applying this rule would have meant the city would win and that Catholic Social Services cannot discriminate in working with the city to place foster kids.

But instead of either applying the Smith rule or reversing it, Roberts’ convoluted opinion claimed that the facts of the case didn’t fit under Smith because the Philadelphia rules are not in fact “generally applicable.” Roberts first noted that the city rule saying a provider can’t reject foster parents based on sexual orientation ends with the words “unless an exception is granted by the Commissioner.” This, Roberts insisted, showed that the law wasn’t generally applicable and instead constituted a system of “individualized exemptions.”

As it turns out, no exceptions have ever been granted. And the city said in court that the exception in question doesn’t refer to an exception for the provider but rather is an escape-hatch if the city doesn’t want to place a child with a particular family.

To avoid applying the Smith rule, Roberts added a second argument that was even more forced. The city had argued that Catholic Social Services had violated an antidiscrimination ordinance that applies to “public accommodations” like restaurants, hotels and swimming pools. Roberts held that adoption agencies aren’t public accommodations under the Philadelphia ordinance because they make individualized judgments about who can adopt.

Despite the duct-tape-and-chewing-gum aspect of Roberts’ logic, it was compelling enough to get Kavanaugh and Barrett to sign on, along with the court’s three liberals — who wanted to retain Smith, even though it effectively meant ruling against gay foster parents. The other three conservatives on the court issued or joined concurrences that show it would be misleading to call this opinion “unanimous” despite the 9-0 result.

Gorsuch, in a concurrence joined by Thomas and Alito, devastated Roberts’s strained efforts to avoid the Smith rule. Alito felt moved to write his own concurrence, joined by Thomas and Gorsuch. And Barrett offered her own concurring opinion, joined by Kavanaugh and in part by Breyer.

Barrett clerked for Scalia and considered him her most important intellectual mentor. For her, in her concurring opinion, to express a willingness to reconsider the Smith rule reflects the recognition, shared by many around the late justice, that he himself was beginning to question his Smith decision towards the end of his life as most other conservatives rejected it.

Barrett’s vote in the Philadelphia case shows that she intends to think the Smith precedent over. Whatever she concludes is likely to become law in this contentious area.

Noah Feldman is a Bloomberg Opinion columnist, host of the “Deep Background” podcast, and a professor of law at Harvard. He was a clerk to U.S. Supreme Court Justice David Souter.