The tide of drug prohibition is turning. With the decision of voters in Colorado and Washington state last year to not just decriminalize but legalize marijuana outright, I believe the nation arrived at a tipping point.

Polling shows people are increasingly open to the notion that not all drugs should be outlawed. A survey by Pew Research Center back in March found a majority of Americans - 52 percent - now say marijuana should be legal. More strikingly, 72 percent agreed that government efforts to enforce marijuana laws cost more than they are worth, and three in four agreed the drug has "legitimate medical uses."

[Check out our gallery of political cartoons.]

Last night, a uniquely credible voice joined the growing cacophony calling for the U.S. to rethink its drug policies. In a documentary special, neurosurgeon and CNN chief medical correspondent Sanjay Gupta offered what amounts to a mea culpa for his previous opposition to medical marijuana. "We have been terribly and systematically misled for nearly 70 years in the United States, and I apologize for my own role in that," he wrote in an accompanying op-ed.

In both the TV special and the column, Gupta shares the story of little Charlotte Figi, whose severe form of epilepsy was subjecting her to as many 300 life-threatening seizures a week – until, at the age of five, she began to take medical marijuana, and the seizures all but ceased completely.

Desmond Tutu once said that "the texture of our universe is one where there is no question at all but that good and laughter and justice will prevail." But there's no justice in keeping a drug on the schedule 1 narcotics list that has the potential to reduce the suffering of millions like Charlotte Figi. There's no justice in perpetrating a "war" on drugs that puts hundreds of thousands of nonviolent, victimless offenders in jail.

[Weigh in: Is Sanjay Gupta Right About Medical Marijuana?]

Today in America, one in every 15 black men is behind bars. According to the Prison Policy Initiative, that means an African-American male is more likely to be incarcerated here, in the land of the free, than in South Africa during Apartheid when Tutu spoke those famous words. Human Rights Watch says people of color are no more likely to use or sell illegal drugs than whites, yet they're arrested far more often. There's no justice in that.

Which is why it's no surprise the tides are changing.

