1) It would save billions of dollars of government waste. The prison system - especially now that much of it is a for-profit industry - is quite corrupt and wasteful. There is a major financial incentive to keep the prisons full. That is in no way helping anyone stay off of drugs.
There are other ways to fix this problem. First, non-violent crimes, such as drug possession, should only result in a prison sentences if they are repeat offenders and refuse to participate in a drug rehabilitation program. But simply ignoring the problem, and saying "Too many people are going to prison for this, so we should just make it legal" won't work. If 80% of people in prison were there because of murder, would we legalize murder?
2) It would eliminate a huge crime element in our country. The street-level drug dealing is by far the major source of violent crime in America. Eliminate the turf wars, the gang control, the cop vs. dealer violence, etc, you have much safer streets in our country.
True, but we should eliminate this problem, without making a different problem worse. Legalizing drugs would make crime rates, directly dealing with drugs, go down. However, it would make general drug addiction much worse of a problem, and in doing so make problems such as burglary worse, as less people are willing to work to support their drug problems.
3) It would cause a serious change in the social climate in the poorest neighborhoods. For many, many kids growing up in that environment the only role models are the dealers. they have the money, the guns, the power, the girls and the glory. They also have a life expectancy of less than 30 years. If drug dealers weren't the idols of the neighborhoods, maybe inner-city kids could and would find others to inspire them and make them believe they have other options.
The benefits of this would definitely not outweigh the negatives of more drug addictions.
4) We could finally get SERIOUS about treating those who are addicted. I know you truly believe that people only ever go to rehab because they are forced to, but it's simply NOT the truth. You cannot assume that everyone addicted to drugs WANTS to be, CHOSE to be, and will fight any and all attempts to end their addiction. There are lots and lots of great ideas and programs that have shown great success in some of the hardest-hit drug-infested areas of the country. But they have no funding and no support - because the police/court/prison system would lose their financial gravy train. With the billions saved by legalizing drugs - just a small portion of those funds could boost these programs to hugely successful levels.
I didn't say people only go to rehab because they are forced too, but they mainly do. They find different motivation for staying in rehab after a few months or years of it. We can not make a person change with force, but we can make some of them want to change with force. I know that most people addicted to drugs don't want to be, but if we make it easier for them to be that way, they will stay that way. Let me make an example:
We're in a desert, it's a terrible, awful desert, many people are trapped in, that don't want to be. However, there is a huge mountain, and on the otherside of that mountain, is great acres of lush land, geen pastures, fresh water, etc. If we can find the strength to climb the mountain, then we will finally be free, on the otherside. However, many people try, and can't make it past the first, and most difficult part of the climb, and many others have the strength too, but just don't realize it. So we start forcing some people to start the climb. Giving them tools to learn how to climb, how to become stronger. Over time, they gain motivation, tools, and confidence in themselves to climb the mountain, and begin really doing it by themselves; and it is at this point they become strong enough to finish the climb. But if we hadn't forced them to start, they never would have gotten that far.
5) We could finally free up our police and courts to be agressive about REAL crime. I would much rather see police patroling the neighborhoods and being PRESENT rather than buying an ounce of crack to make another misdemeanor arrest for the sake of boosting crime statistics.
And real crime would increase. As I mentioned before, burglary rates would go up.