I have a few principles at work here:

1. Drug laws should target dealers, not users.
2. Pot should be legal, but cocaine and heroin should not be.
3. Even if it's illegal, it will happen. That does not mean it shouldn't be illegal. The government doesn't exist to eliminate crime, but limit it. For example, homicide will always occur, even if it's illegal.
4. The government should have a zero-tolerance policy for organized crime. We are far too lenient. The trick is, to make drug sales economically unprofitable. It is, theoretically possible that we could legalize it and put a very malicious price control on it. Another solution would be the use of focusing more effort and funding into fighting off these criminals. If the government was as concerned with keeping the streets clean as it was with say, spying on us, I just don't really see larger gangs being able to compete.