"Should we willingly accept the return of opium dens and all of the miseries associated w/ that natural consequence to drug legalization?"
No, we should insist that our government (at all levels) FOLLOW THE LAW (The Constitution). That would mean a complete elimination of all *federal* laws criminalizing drugs.
The matter would then be for each state (or locality) to argue and worry about, and come up with whatever solution seemed best for them.
If the solution WAS opium dens in California or San Francisco (to pick an example)...and such dens made California or San Francisco
h@ll-holes, then the people of the state or city would either: 1) re-criminalize opium, 2) tax it out the wazoo, to cut down on demand, 3) move out of the state or city, or 4) some other solution.
This country was absolutely NOT intended to have decisions on drugs made at the federal level. In fact, the federal government is violating The Law (the Constitution) by criminalizing the possession and within-state sale of ANY drug.
There should be no debate on this matter (except whether or not the federal government is following the Constitution...which it is not). The People (or at least conservatives and libertarians, because obviously liberals are hopeless) should INSIST the the federal government follow The Law (the Constitution). That requires an immediate end to all laws criminalizing the possession and within-state sale of any drug.