The Little Sisters requested an exemption from the mandate, like the government gave to churches. HHS refused, reasoning that their employees “are less likely than individuals in plans of [houses of worship] to share their employer’s… faith and objection to contraceptive coverage on religious grounds.” In other words, the agency supposed that people who work for the Little Sisters—a group of nuns vowing obedience to the Pope!—are less likely than church employees to adhere to the teachings of the Roman Catholic Church. This blinkered approach to faith serves as a testament to how out of its league HHS was.

Accordingly, in a brief we filed for the Cato Institute, we asked the justices to resolve an additional, threshold question: whether HHS has the authority to craft religious accommodations—rather than grant faith-based exemptions. Congress didn’t authorize executive agencies to pick and choose which religious groups—churches yes, cloisters no—can be exempted from parts of the “preventive care” mandate. In the absence of this authority, the administration’s only recourse is to exempt groups whose religious exercise is substantially burdened by the mandate.

Ironically, the precedent that most supports the Little Sisters’ claim is King v. Burwell, in which the Supreme Court upheld the payment of billions of dollars of subsidies in states that declined to establish health-care exchanges. But in doing so, Chief Justice John Roberts’ majority opinion rejected the Treasury Department’s interpretation of Obamacare that gave itself such awesome power. Roberts found that Congress could not have delegated this vast authority to the IRS in an area of “deep ‘economic and political significance,’” in light of the fact that the agency has “no expertise in crafting health insurance policy.”