GenericMind, I understand what you're saying and I fully support treatment programs for addicts like methadone, needle exchange, even "prescription" heroin. However, this is a far cry from
legalization. I don't think any society has ever tried flat-out legalizing heroin or crack, and I think the results would be very bad if they did. Imagine being able to walk into your local liquor store and pick up a bag of uncut heroin for the same price as a fifth of JD. (Hmm, did I just hear a faint sound like a million BlueLighters all screaming "YESSS!"?

) Seriously, though, substance abuse would get a lot worse than it is now, and while some people are able to function/hold down jobs/raise a family on junk, a great many can't. How many kids would go hungry because mommy would rather get her fix?
I think those of us who are drug users tend to underestimate the barriers to access experienced by "normal" citizens. A lot of people are not willing to make heroin deals in housing-project stairwells, or risk going to prison. Pull those barriers down and use would definitely go up. How much is the question. Personally, I think it'd be pretty huge, and society would not be able to easily cope.
I'm all for scaling back the drug war to apply only to serious drugs of abuse. Maybe one day we can legalize those too, but I would be a lot more comfortable taking it slow.