Trying to predict Supreme Court rulings based on oral arguments is a risky proposition, but the writing that was on the wall on Friday did indeed make it onto the pages of today’s opinions in the federal vaccine-mandate cases.

It’s not surprising that the justices blocked the federal mandate for private-sector workers to get vaccinated or get weekly COVID tests on their own time and dime. After all, even if we accept federal regulation of workplace safety as constitutional, there’s a difference between occupational risk and the general risk of living in a pandemic.

“OSHA’s indiscriminate approach fails to account for this crucial distinction,” the Court majority wrote, “and accordingly the mandate takes on the character of a general public health measure, rather than an “occupational safety or health standard.” Moreover, as Justices Gorsuch, Thomas, and Alito pointed out separately, the federal government lacks a general police power, so statutory text better be clear and explicit when an agency purports to read it as assigning massive regulatory authority—what’s known as the “major questions doctrine”—which is certainly not the case here.

As to the healthcare-workers mandate, that’s a closer call because it’s a question of what kind of strings the federal government can attach to its own program funds—here Medicare and Medicaid—and through what processes it attaches those strings. The Court ruled 5–4 (with Chief Justice Roberts and Justice Kavanaugh joining the Court’s progressive wing) to allow this mandate to stand, at least on a temporary basis while litigation continues in the lower courts—but the four dissenting justices make a strong case that the federal agency overreached here too. As Justice Thomas wrote, “the Government had found virtually unlimited vaccination power in definitional provisions, a saving clause, and a provision regarding long-term care facilities’ sanitation procedures,” but that regulatory patchwork wasn’t exactly a specific power to impose vaccines across facilities.

In any event, the Court today showed that it’s possible to take statutory limits on federal power seriously, not just constitutional ones. To those who accept that basic premise, it’s no surprise that OSHA’s vaccine mandate went the way of the CDC’s eviction moratorium.

For more, listen to my Cato Daily Podcast — recorded yesterday but eerily tracking today’s outcomes.