>THE CONSTITUTIONAL WAY.
very tricky to do anon,
The current controlled substances act is based upon the federal governments authority under the interstate commerce clause. The individual states have no such authority to prohibit substances.
IF the US government decriminalizes cannabis it may ruin any chance of any state to prohibit it.
Re-scheduling cannabis and removing it from schedule 1 to a more reasonable level also has it's perils.
So it's not easy to just give the decision back to the states