Legalize all of them, but no money for treatment or rehabilitation.
Only federal requirement should be “can only be sold in PURE FORM”.
States shall be responsible for picking up the overdose corpses and disposing of the garbage.
The problem with that approach is that there is a set of pathological behaviors that go along with drug abuse, and which have serious effects on non-addicts. Drug addicts who cannot work due to the addiction turn to crime, both to get money to buy their next fix, and because the addiction destroys crucial parts of the brain related to self-control. Many drug addicts end up on the streets as homeless, creating unpleasant and filthy environments that, unfortunately affect everyone. Been to San Francisco lately? You can see exactly what I am talking about there. There is also the effect on families. Many of those drug addict bums once had families that loved them. Imagine being the mother of a drug addict, trying to get your beloved child off the drugs, but no amount of love can overcome the siren song of the next fix.
I would not mind if there were a way to allow drug addicts to dope themselves to death, if only there were ways to shield other people from the effects.