On Marijuana and Guns, Clarence Thomas Still Wants To Limit Federal Power

The conservative justice continues to wage a lonely legal crusade over the Commerce Clause.

The U.S. Constitution gives Congress the authority "to regulate Commerce…among the several States." In 2005, the U.S. Supreme Court held that the Interstate Commerce Clause should be construed so broadly as to allow the federal ban on marijuana to be enforced against medical marijuana patients whose use was perfectly legal under state law and whose cultivation and consumption of the plant had occurred entirely within the confines of a single state.

The final vote in that controversial case, Gonzales v. Raich, was 6–3. The most forceful of the dissents was written by Justice Clarence Thomas. "If Congress can regulate this under the Commerce Clause," he protested, "then it can regulate anything—and the Federal Government is no longer one of limited and enumerated powers."

Thomas does not always favor such strict limits on federal authority. Earlier this term, for instance, he not only voted in support of President Donald Trump's unilateral tariff scheme, but Thomas also endorsed a sweeping vision of executive power that would unshackle the president from normal constitutional constraints when foreign affairs are supposedly involved.

Yet Thomas remains in favor of limiting federal power when marijuana happens to intersect with the Commerce Clause. This was made evident again last week in the Supreme Court's effectively unanimous decision in United States v Hemani, which found the federal prosecution of a marijuana user for possessing a gun to be in violation of the Second Amendment's right to keep and bear arms. "We do not question that sometimes an individual's unlawful use of marijuana (or any other controlled substance) may render him a danger to others," Justice Neil Gorsuch wrote for the majority. But here the government "asks us to conclude that anyone who regularly uses marijuana is categorically violent and dangerous without any further showing," and the Gorsuch-led Court was unwilling to accept that.

"I join [the Court's] opinion in full," Thomas wrote in concurrence. But then, as he sometimes does, Thomas proceeded to write a solo opinion that pushed an even more aggressive legal theory than anyone else on the Court was apparently willing to cosign.

That theory was this: "As a matter of both original meaning and this Court's precedents," Thomas wrote in Hemani, "Congress lacks the power to regulate the possession of firearms solely on the ground that they crossed state lines at some point in the past." In other words, according to Thomas, the federal law that makes it illegal for "unlawful users" of drugs to possess firearms is unconstitutional on its face because Congress has no legitimate authority to criminalize a drug user's "intrastate gun possession."

This is basically the same reading of the Interstate Commerce Clause that Thomas championed way back in Raich. "As an original matter," he wrote last week in Hemani, quoting from his Raich dissent, "the Commerce Clause authorizes Congress only 'to regulate the buying and selling of goods and services trafficked across state lines.'" And because the federal law at issue in Hemani "criminalizes possession of firearms apart from any purchase or sale of goods and services across state lines," he continued, "I doubt that it could be an exercise of Congress's Commerce Clause powers as an original matter."

I have long thought that Thomas had the better argument in Raich and that Justice John Paul Stevens' majority opinion deserved to be overruled. The fact that Thomas is still basically waging the same lonely crusade two decades later, however, does not lead me to expect that result anytime soon.