Marijuana should be legalized as quickly as possible. Big money interest only want it illegal because it furthers their own financial interest. For instance, it offers immediate competition to alcohol. Also, should it become legal, the scores of law enforcement activities around it are no longer needed. It's time to face the fact that the war on drugs is a failure.
Where I live now, marijuana is legalized. It can be purchased and the shops around here are becoming as common as a 7-Eleven store. I am not a user, but I do know that the amount of revenue it is generating from the sales is helping the government to provide programs that were once unable to provide funding. You can try with big money, that's what happened here, and it didn't win.
Serious negative effects of consuming marijuana have not been proven in a compelling manner. The societal costs of enforcing marijuana laws have grown while the benefits of prohibition have not been supported by reliable data. It remains the responsibility of the individual to control when and how much of a narcotic she/he consumes (this includes alcohol).
I believe that marijuana should be legalized for both recreational and medicinal purposes. The government currently spends billions of dollars a year fighting a losing war on drugs. We would be much better off if we regulated and taxed marijuana to collect revenue from a drug which people are already using.