Photograph by Mark Wilson/Getty

The great Oliver Wendell Holmes once observed that important Supreme Court decisions “exercise a kind of hydraulic effect.” Even if the authors of such decisions assert that their rulings will have limited impact, these cases invariably have a profound influence. So it has been with Burwell v. Hobby Lobby Stores, Inc., which is less than six months old.

In Hobby Lobby, a narrow five-to-four majority of the Court held that the Religious Freedom Restoration Act of 1993 gave the proprietors of a chain of retail craft stores the right to exempt themselves from certain provisions of the Affordable Care Act. Specifically, the A.C.A. requires firms with more than fifty employees to provide insurance that includes birth-control coverage, or else pay a fine. There was an exemption already for religious institutions. Hobby Lobby, a closely held corporation, is a secular, for-profit business, but the Court held that because the owners of Hobby Lobby held a sincere religious belief that certain forms of birth control caused abortions, they could deny employer-paid insurance coverage for them. Justice Samuel Alito insisted, in his opinion for the Court, that his decision would be very limited in its effect. Responding to the dissenting opinion by Justice Ruth Bader Ginsburg, who called it “a decision of startling breadth,” Alito wrote, “Our holding is very specific. We do not hold, as the principal dissent alleges, that for-profit corporations and other commercial enterprises can ‘opt out of any law (saving only tax laws) they judge incompatible with their sincerely held religious beliefs.’ ” Ginsburg, though, wondered where the guidance was for the lower courts when faced with similar claims from employers with religiously grounded objections to blood transfusions (Jehovah’s Witnesses); antidepressants (Scientologists); medications derived from pigs, including anesthesia, intravenous fluids, and pills coated with gelatin (certain Muslims, Jews, and Hindus); and vaccinations (Christian Scientists, among others).

The exchange between the two Justices gets to the heart of the issue in Hobby Lobby. When do religious convictions allow individuals (or corporations) to excuse themselves from obligations that are binding on everyone else?

A sampling of court actions since Hobby Lobby suggests that Ginsburg has the better of the argument. She was right: the decision is opening the door for the religiously observant to claim privileges that are not available to anyone else.

One such matter is Perez v. Paragon Contractors, a case that arose out of a Department of Labor investigation into the use of child labor by members of the Fundamentalist Church of Jesus Christ of Latter-day Saints. (The F.L.D.S. church is an exiled offshoot of the Mormon Church.) In the case, Vernon Steed, a leader of the F.L.D.S. church, refused to answer questions by federal investigators, asserting that he made a religious vow not to discuss church matters. Applying Hobby Lobby, David Sam, a district-court judge in Utah, agreed with Steed, holding that his testimony would amount to a “substantial burden” on his religious beliefs—a standard used in Hobby Lobby—and excused him from testifying. The judge, also echoing Hobby Lobby, said that he needed only to determine that Steed’s views were “sincere” in order to uphold his claim. Judge Sam further noted that the government had failed to prove that demanding Steed’s testimony was not, in the words of the R.F.R.A., “the least restrictive means of furthering that compelling governmental interest.” That burden seems increasingly difficult for the government to meet.

The Supreme Court itself has suggested that the implications of Hobby Lobby were broader than Alito originally let on. Just days after the decision, the Court’s majority allowed Wheaton College, which is religiously oriented, to refuse to fill out a form asking for an exemption from the birth-control mandate—while retaining the exemption. There is another case, Little Sisters of the Poor v. Burwell, which is also pending, where a religious order asserts that the filling out of a form (which, if granted, would exempt them from the law’s requirements) violates their rights.

If just filling out a form can count as a “substantial burden,” it’s hard to imagine any obligation that would not.

Some religious universities are relying on Hobby Lobby to argue that they must be excused from bargaining with labor unions.* *Hobby Lobby is a large, but family-controlled, company; now other companies, with broader ownership groups, are claiming the right to impose their religious beliefs on their employees. What about minimum-wage laws that eat into the coffers of religious organizations, or just religious businessmen? What about religious individuals who say that they have sincere objections to conducting business relationships with gay people or immigrants? Will they be excused from honoring the nation’s anti-discrimination laws? All these issues are now unresolved. The Becket Fund for Religious Liberty, a conservative public-interest legal group, is dedicating itself to expanding the reach of the Hobby Lobby decision.

Some lower-court judges may recoil at these attempts; others will welcome them. But the Supreme Court, having opened the door to these cases, appears unlikely to shut it any time soon.