I agree, but let me try to clear up where I've been confusing.
1) Comparisons that try to map marijuana onto other substances are misleading and often incorrect. This would be no different than comparing, say, antibiotics to psychiatric medications -- different chemical entities, different ways to dose, different outcomes. We are in complete agreement here, although I think others do want to compare because in some ways, marijuana comes off as less harmful than things we already allow.
2) Comparisons by policy and behavior. This works better because we can generalize. When all drugs in Schedule II are prosecuted similarly, it's fine to compare them. When human behaviors are similar, that's useful too. So, for example, if we are talking about someone committing a crime to make a buck, in the general sense, we don't care if they are embezzling from their employer or selling fake art -- as long as the focus is on committing a crime for money, the similarities might be relevant.
I don't dispute this. In fact, I think it's wrong to say that any substance is inherently harmful, they are just molecules doing their thing. Even at the level of the user, I agree with NORML on their "responsible use" goal. But there's more on offer.
The underlying argument is about harm to society overall. I'll give you what may seem a silly comparison, but might make it clearer.
Pool halls are sometimes viewed as hang-outs for the less-than-savory and dens of iniquity. Before they became family friendly, many were smoke-filled hangouts for ne'er-do-wells and the "criminal element." I can remember at least one local fight to prevent a pool hall from opening up.
No one claims there's something about playing pool that makes anyone a miscreant, but the reputation arose of a link. If you wanted to find the loan shark or the juvenile delinquent, a pool hall was a good place to look.
A community might say, "Hey, we know there are people, good people, people like us who are solid citizens, who enjoy playing pool. But it's not worth the other stuff that comes with it and we are only pissing off these few, so we'll keep it out of our neighborhood."
Now, getting back to marijuana. Portugal was mentioned earlier as a place where decriminalization worked out. It's interesting to see that drugs are not legal there, but have a lower penalty for possession. Manufacture, sale and trafficking are still criminal. They've also added a huge amount of resources for treatment.
I have one question then. Why is marijuana use prohibited? Of the 80 countries listed in Wiki's entry on the subject (
http://en.wikipedia.org/wiki/Legality_of_cannabis_by_country), all regulate and penalize marijuana at some level.
Explanations that revolve around US specific rationales shouldn't apply world wide, should they? Is there something about marijuana that makes it a target other than perceived harm?