Justice Scalia said otherwise, in the Raich decision.
And a fellow by the name of Stewart was jailed for possession of an unregistered machine gun that he made himself (I think from scratch), that never left his house. Funny case, that one, as the 9th Circuit said the weapon was not involved in interstate commerce, so he (Stewart) was not afoul of federal law. The US Supreme Court told the 9th Circuit to apply Raich in order to find him guilty.
Those along with Row vs wade and Kelo show just how screwed up this country has become.