Following the U.S. Supreme Court’s refusal to hear a cannabis tax case Monday, Justice Clarence Thomas issued a statement questioning whether the federal government’s continuing ban on marijuana cultivation and use “is necessary or proper” given its widespread legalization among the states.

In a five-page statement “respecting the denial of certiorari” in Standing Akimbo v. United States, Thomas criticized the federal government’s “half-in, half-out regime” that simultaneously condones state-level medical marijuana use but refuses to allow dispensaries to deduct business expenses from their taxes.