In 1941, an Ohio farmer named Roscoe Filburn planted more wheat on his farm than the Agricultural Adjustment Act of 1938 permitted. He did not sell the wheat on the open market.  Rather, he fed the wheat to his livestock.  The Secretary of Agriculture imposed a penalty on Filburn for the excess.  Filburn sued, alleging that he had engaged in no commerce at all, let alone interstate commerce.

The District Court agreed and enjoined the penalty.  The Supreme Court unanimously reversed.  It acknowledged that Filburn had not engaged in any transaction.  Had he not violated the quota, however, he would have had to buy wheat on the open market.  The Court also acknowledged that Filburn’s contribution to higher priced wheat was trivial.  Combined with the similar actions of others, however, the effect on price was anything but trivial.  Thus, Congress had the authority under the commerce clause to regulate Filburn’s wheat.

In the years following, courts repeatedly relied on this aggregate theory of commerce to justify federal regulation of many items.  The constitutional foundation for the 1964 Civil Rights Act, for example, was the commerce clause, not the 14th amendment.  Similarly, the basis for federal regulation of purely intrastate sale of medical marijuana was the aggregate theory.  A number of courts have relied on that theory in sustaining the constitutionality of the Endangered Species Act (ESA) when applied to purely intrastate activities.

Two pending cases may overturn that result.  In People for the Ethical Treatment of Property Owners v. U.S. Fish & Wildlife Service, the Service designated the Utah prairie dog as an endangered species, though it subsequently downgraded the status to threatened.  The Utah prairie dog resides exclusively in Utah and there is no commercial market for it.  Plaintiff argued that the Service’s effort to regulate it exceeded Congress’ commerce clause powers.

The District Court agreed.  The Service’s principal argument was that the designation affected interstate commerce because it frustrated several proposed commercial and agricultural activities.  Relying on Supreme Court precedent involving guns near schools and violence against women, the District Court held that the proper focus was on the regulated activity – i.e., the prairie dog – and not the activity that the regulation prohibits.

The Service also argued that protection of the Utah prairie dog had a substantial effect on interstate commerce, because the dog was a source of food for predators like bald eagles that did affect interstate commerce.  The District Court held that the commerce clause allowed Congress to regulate commerce, not ecosystems, and the possible effect on other predators was purely speculative.  The case is currently on appeal to the Tenth Circuit.

A similar case, American Stewards of Liberty v. U.S. Fish & Wildlife Service, is pending in the United States District Court for the Western District of Texas. The protected species there is the Bone Case harvestman (BCH), a tiny blind spider that inhabits caves in two counties in central Texas.  There is no market for the creature and no other species relies on the BCH as a source of food.

In 2003, over a spirited dissent, the Fifth Circuit upheld the Service’s listing of the BCH as within Congress’ commerce clause powers. GDF Realty Investment, Ltd. v. Norton.  In so holding, GDF applied the deferential rational basis standard.  In subsequent Supreme Court cases – Gonzales v. Raich, and NFIB v. Sibelius – the Court clarified that the correct standard for such challenges is the much more demanding necessary and proper clause, which requires that the challenged regulation be “plainly adapted” to the execution of an enumerated power.  A regulation is “plainly adapted” if it is narrow in scope, incidental to the regulation of commerce, and does not work a substantial expansion of federal authority.  The intervenor plaintiffs’ motion for summary judgment is pending.

While the legal issues may be fairly dry and technical, the practical consequences of these cases are potentially immense.  It is illegal to “take” a threatened or endangered species.  The statute defines “take” very broadly:  harassing, harming, hunting, pursuing, shooting, wounding, killing, trapping, capturing, or collecting, or any attempt to do so.  Violations can result in civil penalties, criminal fines of $50,000 per violation and one year in prison.

As a result, development of property that is occupied by a threatened or endangered species is highly restricted.  The owner can seek a permit from Fish & Wildlife to develop property, but the cost of complying with conditions attached to the permit may be prohibitive.