Persistent nonsense.
Bravo sierra.
Where in the Constitution has the federal government given any authority to prohibit anything? The invocation of the interstate commerce clause is really the "persistent nonsense" - if it were invoked constitutionally, there could be no law passed preventing citizens from growing marijuana or any other psychoactive plant on their property for their own use, but we all know how far that would get :-(.
The temperance movement types realized that it would be unconstitutional to pass a federal law banning booze in the early 20th century and successfully sought a Constitutional amendment giving the government that authority. It promptly exercised that authority with the Volstead Act, and ushered in 14 years of lawlessness known as Prohibition. Thankfully, common sense eventually prevailed and that abomination of liberty was repealed. You Drug Warriors, however, hide behind the generalized raping of the Constitution that was justified by FDR's New Deal, and never saw fit to change the Constitution to further your goals.
That's why drug prohibition is UNCONSTITUTIONAL.