In my column today about bogus objections to California's marijuana legalization initiative, I noted the argument that Proposition 19 is unconstitutional. Nine former heads of the Drug Enforcement Administration repeat that claim in today's Wall Street Journal:

If passed by voters in November, Proposition 19—also known as the Regulate, Control and Tax Cannabis Act of 2010—will be in direct conflict with the Controlled Substances Act (CSA), a federal law that makes the production and sale of marijuana a federal crime. In our federal system, a state law that conflicts with a federal law violates the Supremacy Clause of the U.S. Constitution and is void.

The CSA itself clearly states that federal law overrides state law when there is a positive conflict between the two jurisdictions. Thus there is very little likelihood that anyone is going to be paying sales taxes to the state of California or its municipalities when to do so would be admitting the commission of a federal felony.

The legal argument sounds superficially plausible, especially since the Supreme Court, based on a ridiculously broad reading of the Commerce Clause, has upheld national marijuana prohibition, even as applied to purely intrastate cultivation and possession of the drug by patients who are permitted to use it under state law. But it is one thing to say that the federal government may arrest patients for growing or possessing medical marijuana. It is quite another to say that the U.S. Constitution requires every state to arrest those patients too, which is what these former narcs in chief are claiming. A system that required states to ape every aspect of federal law—permitting what Congress permits, prohibiting what it prohibits, and applying criminal sanctions accordingly—would obliterate the last vestiges of federalism. Commandeering state and local officials to enforce a ban on a product that Congress deems unacceptable—something that did not happen even during alcohol prohibition, which unlike marijuana prohibition was constitutionally authorized—cannot possibly be reconciled with the 10th Amendment: "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."

As for the claim that no one will pay taxes on marijuana because growing and selling it will still be a federal crime, it has already been proven false. California collects something like $100 million in sales tax revenue from medical marijuana dispensaries every year, even though the drug is still prohibited for all purposes by the CSA.

More on the constitutional objection to Prop. 19 here.