Free states have prohibitions on illicit drugs. All fifty states.
If their state constitutions allow that, then I don't question the constitutional legitimacy of those state laws.
However some states are attempting to change their position. Predictably, the fed is ignoring the states 10th Amendment prerogative to do so.
The fed needs an amendment to pass such laws for the states, as it did with alcohol. But that all changed with FDR's commerce clause. Not that you mind...