Quote Originally Posted by Cojafoji View Post
It's a question of the enumerated powers of the federal government as set forth by the tenth amendment. All powers not specifically laid down in the constitution or following amendments are to be inherited by the states as reserved powers. The real problem is the national regulation of the CSA (controlled substances act) which allows the federal government to lump a lot of drugs/meds/plants etc in one big group that the government can legally tax (and in most cases restrict the ability to pay the tax, therefore making it illegal).

Honestly, this is a US Supreme Court case in the making.
Basically this. I'm sure there are many state and local laws that actually violate federal law; it's just that they don't get repealed until the courts say it has to be after a case was brought up involving that law. That's just how it works here in the USA. Any court can actually call a law unconstitutional, but it can be appealed up through to the Supreme Court.