hab·i·tat ˈhabəˌtat/​noun: The natural environment of an organism, the place that is natural for the life and growth of an organism; the natural home or environment of an animal, plant, or other organism.


Seems straightforward, right? Unless, of course, you’re the U.S. Fish and Wildlife Service (FWS), which in its role administering the Endangered Species Act (ESA) classified land where a species doesn’t live and can’t survive as “critical habitat” that is “essential” to the survival of that species. Yes, FWS redefined basic terms in the English language and designated a parcel of land in Louisiana as critical habitat for the “dusky gopher frog,” despite the parcel’s utter unsuitably for sustaining the frog’s life cycles.


When the Weyerhaeuser company challenged the FWS designation, first the district court and then the U.S. Court of Appeals for the Fifth Circuit applied Chevron—the doctrine whereby courts give hands‐​off treatment to agencies when they interpret statutes—and deferred to the agency’s rule. This, even though Chevron itself doesn’t allow “arbitrary and capricious” interpretations.


The Supreme Court agreed to hear the case. Cato has now filed a brief supporting the property owner, joined by the New England Legal Foundation. We argue that the FWS interpretation of the ESA is unreasonable and that this aggrandizement of federal power to regulate property goes beyond constitutional limits. The idea that land that is uninhabitable for a species is nevertheless “essential” to its survival is unmoored from even government logic.


Put simply, the FWS effectively rewrote the ESA in a way Congress never authorized—and could not constitutionally permit. Even if one accepts that the ESA fits into Congress’s power to regulate interstate commerce—in which case critical‐​habitat designation is undoubtedly a necessary part of the scheme—that power has limits. Mere existence of land does not constitute “economic activity” under the Commerce Clause; if it did, all land in the United States would be subject to federal jurisdiction (as is the case in federal enclaves). Likewise, the regulation here doesn’t fit into the Necessary and Proper Clause. It’s not necessary because the land at issue plays no role in the frog’s conservation; it’s not proper because it infringes on state sovereignty over land‐​use regulation.


As Judge Priscilla Owen nicely summarized in her dissent from the Fifth Circuit’s decision, the practical implications of the flawed ruling are immense: “If the Endangered Species Act permitted the actions taken by the Government in this case, then vast portions of the United States would be designated as ‘critical habitat’ because it is theoretically possible, even if not probable, that land could be modified to sustain the introduction or reintroduction of an endangered species.”


When it hears Weyerhaeuser v. U.S. Fish & Wildlife Service this fall, the Supreme Court should reverse the lower courts’ determination to allow the federal government to control everyone’s backyards for no particular reason.