Well, here's my two penn'orth.
Some currently illegal drugs are more addictive/ dangerous than others
Sale of illegal drugs makes huge profits for criminals.
The fact that some drugs ( eg Pot) are widely felt to be "acceptable" but are still illegal brings the law into disrepute. People who are otherwise law-abiding buy & consume such "soft" drugs and do not feel that it is morally wrong. HOWEVER, much of the profit from sale of these "soft" drugs, goes to the same gangsters who deal in the "hard" drugs.
This is very similar to the prohibition days in the US when criminals made fortunes on booze, and were regarded as "the good guys" by many otherwise law-abiding citizens.
So my proposal is this:
Have an open, informed discussion, and agree different categories for each drug.
(For discussion I'll put forward 3 categories. Maybe there should be only 2, maybe 4 or more)

Category 1: Least Harmful
To be sold legally, taxed & controlled, in much the same way as tobacco or booze.

Category 2: Mid Level
Available on a very strictly controlled basis, through pharmacies, and requiring regular medical check-up, paid for by user.

Category 3: Seriously Poisonous Utterly prohibited. Very serious penalties for possession, or use (like 5 years minimum for a first offence) and say 20 to 200 years for dealing.(I do not support the death penalty, but you may feel differently).

I think this would have the following advantages:
(1)Those who take the occasional puff, (inhaled or not :o), or slice of space-cake, at a party, can indulge without feeling criminalised.
(2) More respect for what is seen as a more sensible law should encourage people to support said law.
(3) Profits of the drug barons slashed.
(4) Taxes gained on categories 1 & 2 can be used for medical research/ rehabilitating addicts/ law enforcement/ education about the REAL dangers etc.


Reasoned debate welcomed!