I thought Wickard v. Filburn, 317 U.S. 111 settled that in 1942 when SCOTUS declared that the Commerce Clause permitted Congress to “regulate Commerce...among the several States.” It was wheat in ‘42, not weed. Sounds like the same case, though.
It looks pretty similar. The opinion cites Wickard:
The case comes down to the claim that a locally cultivated product that is used domestically rather than sold on the open market is not subject to federal regulation. Given the CSA's findings and the undisputed magnitude of the commercial market for marijuana, Wickard and its progeny foreclose that claim.
J. Stevens, Opinion of the Court, Gonzales v Raich.