Simple
state sovereignty, and the Constitution of the United States. Here in Michigan, Our Constitution also.
Look into a States *(i believe its) 13th Amendment. The right of a State to withdraw from the Union of the United States.
Go to the back of the line Sparky, that abolishes slavery. It's the 10th amendment that allows states (or the people) to retain all rights not specifically given to the Federal Gov't by the constitution. It's an interesting read for those who wish to google how it was originally drafted, and has been interpreted by the courts over the years. In recent years, the Feds have taken control by the "commerce" clause.
In
United States v. Lopez 514
U.S. 549 (1995), a federal law mandating a "
gun-free zone" on and around public school campuses was struck down because, the Supreme Court ruled, there was no clause in the Constitution authorizing it. This was the first modern Supreme Court opinion to limit the government's power under the Commerce Clause. The opinion did not mention the Tenth Amendment, and the Court's 1985
Garcia opinion remains the controlling authority on that subject.
However the courts contradict this in 2005:
Most recently, the Commerce Clause was cited in the 2005 decision
Gonzales v. Raich. In this case, a California woman sued the
Drug Enforcement Administration after her
medical marijuana crop was seized and destroyed by federal agents. Medical marijuana was explicitly made legal under California state law by
Proposition 215; however,
marijuana is prohibited at the federal level by the
Controlled Substances Act. Even though the woman grew the marijuana strictly for her own consumption and never sold any, the Supreme Court stated that growing one's own marijuana
affects the interstate market of marijuana. The theory was that the marijuana
could enter the stream of interstate commerce, even if it clearly wasn't grown for that purpose and that was unlikely ever to happen (the same reasoning as in the
Wickard v. Filburn decision). It therefore ruled that this practice may be regulated by the federal government under the authority of the Commerce Clause.
Oh how I wish that all 50 would just say "Fuck you Uncle Sam!", and just go ahead and do what they are gonna do as guaranteed by the Constitution. The Feds would surely be fucked then.