This article confronts the idea that the legalization of drugs would be better for society by refuting the oft repeated myth that Prohibition was a failure in decreasing alcohol consumption. And as this is one argument I've used myself while playing Devil's Advocate with the drug issue, I was rather suprised to learn that in 1914, before Prohibtion, the average person consumed 22.8 gallons of alcohol, compared to 8.96 the year after Prohibition ended.
Contrary to myth, there is no evidence that Prohibition caused any big increases in crime. The real facts are these: As a result of Prohibition, 180,000 saloons were shut down, and 1,800 breweries went out of business. In ten years of Prohibition, the death rate due to alcohol decreased 42 percent, the death rate due to cirrhosis of the liver decreased by 70 percent, crime decreased by 54 percent, and insanity decreased by 66 percent." -Rev. Mark H. Creech, Prohibition and the Legalization of DrugsIn light of which it seems almost as foolish to suppose that doing away with speed limits would lead to safer roads. ;-)