The so-called "dormant" Commerce Clause restricts state authority over interstate commerce, even though the text of the Commerce Clause is a grant of authority to Congress.

While there are some originalist defenses of this doctrine, and much evidence that something in the Constitution is supposed to restrict state authority over interstate commerce, a common opinion among many originalist judges and scholars is something like what Justice Thomas argued in his dissent in Camps Newfound: the Commerce Clause should not be read as a restriction on state authority, and instead those restrictions should come from the Import/Export Clause, Article IV's Privileges and Immunities Clause, and the like. (Thomas relies among other things on the great William Crosskey, one of my predecessors as a constitutional law professor at the University of Chicago, and long overdue for a revival.)

This point loomed in the background of the recent oral argument in National Pork Producers v. Ross, the dormant Commerce Clause challenge to California's ban on poorly-housed pork. (For discussion, here is a recent podcast episode.) If the dormant Commerce Clause is on shaky ground, then perhaps it should not be extended to the kinds of extraterritoriality problems in that case.

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