Writing for the motley majority of Justices Ginsburg, Roberts, Scalia, Kennedy, Breyer, Sotomayor, and Kagan, Justice Ginsburg noted that under federal law, Mellouli's concealment of Adderall in his sock would not have been a drug-paraphernalia offense.
As I predicted, the majority held that the government needed to, but did not prove that Mellouli's conviction related to a “controlled substance” as that term is defined in 21 U.S.C. § 802. Proving that the conviction related to a “controlled substance” as that term is defined by state law was insufficient to authorize Mellouli’s deportation.
You can find the opinion here.