Some rules are more obviously important than others. In 2020, Congress imposed a temporary national moratorium on evictions as part of its efforts to combat the Covid-19 pandemic. After it expired, the Centers for Disease Control and Prevention issued its own deportation moratorium under a provision of the Public Health Services Act of 1944, which allows the agency to “provide for such inspection, fumigation, disinfection, sanitation, extermination of parasites, destruction of animals or objects infected or contaminated to the point of being dangerous sources of infection for human beings, and other measures, as in [its] judgment may be required. A group of Alabama homeowners challenged the constitutionality of the ordinance in federal court.

When they asked the Supreme Court to block the moratorium last summer, the justices refused to do so in a 5-4 vote. Justice Brett Kavanaugh wrote a concurring opinion explaining that he voted to keep the order intact until its expiration date about a month later and would vote to block it next time unless Congress reauthorized the moratorium itself. The Biden administration, under pressure from lawmakers and Democratic activists, released a slightly more limited version of the moratorium after the previous one expired. As expected and announced, the Supreme Court quickly struck down the warrant for exceeding the CDC’s statutory powers.

The court based its decision on a fairly straightforward textual reading of the statute in question, which did not mention evictions or housing and instead focused on goods and livestock crossing state lines. “This downstream link between deportation and interstate spread of disease is markedly different from the direct targeting of disease that characterizes the measures identified in the statute,” the court argued. “Reading the two sentences together, rather than the first one separately, it is a stretch to argue that Section 361(a) gives the CDC the power to impose this moratorium on evictions.”

However, it didn’t end there, fleshing out a larger reason for blocking the moratorium. “Even if the text were ambiguous, the very scope of authority claimed by the CDC under Section 361(a) would advise against the government’s interpretation,” he added, citing a line of cases on major issues doctrine. “We expect Congress to speak clearly when authorizing an agency to exercise powers of ‘broad economic and political significance.’ This is exactly the kind of power the CDC is claiming here.