Taylor’s lawyer asked to introduce evidence that all the pot Taylor targeted came from inside Virginia. The trial judge refused, telling jurors instead that the government had to prove beyond a reasonable doubt only that “the defendant reduced the movement of articles and commodities in interstate commerce, in this case, illegal drugs and drug proceeds.” The jury convicted, and Taylor was sent to prison. The Fourth Circuit rather briskly affirmed his conviction, holding that “to focus exclusively on an individual act would wholly undermine Congress’ purpose in adopting the Hobbs Act: to protect commercial, interstate activity from criminal disruption.”

Any discussion of Congress’s power over “commerce among the several states” brings out the persistent myth that if you’re just really, really careful to only use in-state materials, you can somehow completely escape federal regulation. I am not sure what an entirely in-state activity would look like, but it doesn’t matter, because, under the case law, the Commerce Power can reach any “commercial activity” anywhere that “substantially affects” interstate commerce. So the question, first-year students, would be: (1) Is dealing weed a “commercial activity”? (Hint: Yes.) (2) Does the weed market “substantially affect” interstate commerce? (Hint one: Duh. Hint two: In 2005, Gonzalez v. Raich upheld the criminal prohibitions of the Controlled Substances Act, a regulation of “interstate commerce,” even as applied to citizens with California marijuana cards who grew their own pot or got it free from the neighbors.)

On Tuesday, Dennis Jones, Taylor’s hapless but courtly lawyer (it was he who addressed Justice Elena Kagan as “ma’am”) haltingly tried to convince the Court that Taylor should have been allowed to call “a retired DEA agent or an ATF agent or a retired local police officer who had years of experience in that field” to testify that the drugs he was after were local. Virginia, Jones pointed out needlessly, has “the ability to grow marijuana in-state.”

“What difference would that have made under the terms of the Hobbs Act?” Kagan asked. “[T]he Hobbs Act only requires an effect on commerce, and then commerce is defined: Commerce means all commerce over which the United States has jurisdiction. Now, for sure the United States has jurisdiction over interstate commerce, but under Raich, it also has jurisdiction over intrastate drug trafficking. And so, if you just sort of put the pieces of the statutes together, it seems to make it completely irrelevant whether the drug trafficking was intrastate or interstate, because, in either case, it was commerce over which the United States has jurisdiction.”

Jones struggled for the rest of his time to get past that question—and he didn’t get much help from any of the conservative justices, who have, in other cases, worried about federal overreach in the criminal area. Justice Samuel Alito, whose lock-’em-up instincts often seem stronger than his passion for “state sovereignty,” pointed out the paradox of Jones’s argument: Congress can outlaw all growing of marijuana, “but according to you, it cannot prohibit ... the theft of marijuana?” Jones had no real answer for that one; he wandered vaguely into a new argument—that the government hadn’t proved that Taylor’s victims were actual drug dealers at all. Justice Anthony Kennedy, with uncharacteristic sharpness, cut him off: “[T]hat’s not the question presented” in Taylor’s petition for cert, Kennedy said. “Your question presented assumed that he’s a drug dealer, so don’t argue that.”