What have we learned from Prohibition?

Apparently nothing. This past Friday was the 75 anniversary of the repeal of prohibition.

The entire alcohol industry was controlled not by licensed, regulated businesses, but by violent criminals willing to assume the risks of trafficking an illegal product in exchange for obscenely high profits -- profits inflated by alcohol's very illegality.

This new underground environment also transformed alcohol as a product. Bootleggers discovered there was more money to be made with more potent forms of liquor that could more easily be smuggled and hidden. Stealth and transportability, rather than safety, became essential.

And rather than reducing crime, alcohol Prohibition made pretty much everybody criminals, creating an unheard-of level of gang violence and police corruption.

By 1933, these factors, plus the Great Depression and the urgent need for tax revenues that could once again be generated by legal alcohol sales, had caused public enthusiasm for Prohibition to wane. Repeal came quickly and was relatively uncontroversial.

And what do we do today?

According to a 2006 report by George Mason University public policy expert Jon Gettman, marijuana is now by far the largest cash crop in America. At $36 billion a year, it exceeds wheat and corn combined.

Because we refuse to establish sensible regulations and controls on the manufacture and sale of marijuana, every cent goes to criminals and violent gangs. They pay no taxes and answer to nobody for selling to children or operating in an unsafe or irresponsible manner, just like the bootleggers of old.

And yet, according to the most recent FBI Uniform Crime Reports, we arrest more than 872,000 Americans a year for marijuana offenses, and that number has climbed every year for the past five years. That's one marijuana arrest every 36 seconds. And nearly 90 percent of those arrests are for simple possession - not dealing or manufacturing.