New York City, the pot-bust capital of the Western world, is notorious for the racial skewing of its marijuana arrests. Over the last 15 years, more than 85 percent of the half-million-plus people charged with misdemeanor possession there have been black or Latino.

But the racial ratios of reefer roundups are equally extreme—if not worse—in scores of other U.S. cities. In Atlanta, Baltimore, Philadelphia, and Washington, more than 80 percent of the people popped for pot possession are black. In Minneapolis and its Hennepin County suburbs, black people are 11 percent of the population and more than half of those busted for buds.