Prohibitionists rejected the idea that people could be trusted to drink in moderation, arguing that alcohol use inevitably led to moral corruption and undesirable behavior. Accepting these premises led Congress to conclude that a federal ban on the production and sale of alcohol would go a long way toward reducing crime and addressing a variety of other social problems. Within a decade, however, Americans discovered that the criminally enforced prohibition of alcohol produced harmful side effects. The rise of black markets empowered organized crime to an unprecedented degree. In some of America's largest cities, local governments had been heavily corrupted by the influence of organized crime. The black market provided minors with easy access to bootlegged alcohol, which was frequently of poor quality and unsafe to drink. Faced with the disastrous consequences of Prohibition, Congress decided in 1933 to repeal the Volstead Act. Since that time, the government has implemented the much more successful policy of focusing law enforcement efforts on irresponsible alcohol users who endanger the rights of others. Unfortunately, current drug policy fails to take into account the lessons of Prohibition. The law regards all users as abusers, and the result has been the creation of an unnecessary class of lawbreakers.
Current legal drugs such as alcohol and tobacco have a far worse effect on the body than marijuana. No evidence exists that anyone has ever died of a marijuana overdose. Tests performed on mice have shown that the ratio of cannabinoids (the chemicals in marijuana that make you stoned) necessary for overdose to the amount necessary for intoxication is 40,000:1. For comparison's sake, that ratio for alcohol is generally between 4:1 and 10:1. Alcohol overdoses kill about 5,000 yearly but marijuana overdoses kill no one as far as anyone can tell (MacCoun, Rueter, 2001).
Marijuana is psychoactive because it stimulates certain brain receptors, but it does not produce toxins that kill them (like alcohol), and it does not wear them out as other drugs may.