[margalabargala]

Federal drug enforcement has jurisdiction over the states which have passed bills legalizing these products, and it is the stated position of Federal drug enforcement that they will not pursue any enforcement related to these substances in these states.

Thus the products and the businesses are de facto legal, even if they are de jure not.

[chiefalchemist]

That's the point. The states aren't legalizing. They can't. Fed supercedes them. But at the state level they can't choose not to enforce state law, not to prosecute. And that's decriminalization.

[anamax]

That "stated position" is not a legal defense.

[margalabargala]

What makes something illegal? Someone saying "this is illegal"? Or the ability and intent to enforce that statement?

There are plenty of states/cities with old laws on the books calling all sorts of random things illegal. A search for "old unenforced laws" will yield plenty of humorous examples. But the things these old, unenforced laws refer to are not things that are considered "illegal", except generally in the context of articles about old unenforced laws.

What's the difference between a law that says "this is illegal" but the authorities have no interest in actually pursuing, and a law that says "this is illegal" but the authorities have no interest in actually pursuing?

[anamax]

There's no difference between 'a law that says "this is illegal" but the authorities have no interest in actually pursuing' and 'a law that says "this is illegal" but the authorities have no interest in actually pursuing'.

My definition of "illegal" is "you can be arrested, charged, and convicted."

Intent and actors can change. A DA who says "I won't prosecute {x}" is under no obligation to continue, or even be consistent with, that policy, and the next DA is certainly not bound by it.