Courtesy of the American Civil Liberties Union, we now know that there's a racial disparity in marijuana arrests.

The ACLU released the results of its study last week. According to U.S. News & World Report, "the study showed that in 2010 black Americans were around four times more likely to be busted for pot."

The story had other revelations.

"Data gleaned from FBI Uniform Crime Reporting statistics and U.S. Census numbers show that every state except Hawaii had a higher per capita marijuana arrest rate for blacks than for whites, and the disparity appears to be growing in most states. The gap between black and white arrest rates grew in 38 states and the nation's capital between 2001 and 2010."

And yes, there are studies that show black Americans use marijuana less than white Americans do. It appears that, when it comes to law enforcement, the focus seems to be on arresting black Americans, at least for marijuana possession.

So we now know there is yet another downside to what should be derisively called "the war on drugs." Civil liberties have already taken a hit in this so-called war. Now, it appears, so has the notion of racial equality.

If this revelation doesn't sour us on "the war on drugs," I don't know what will or can. My disillusionment with the "war on drugs" came five years ago, after that incident involving marijuana and the mayor of Berwyn Heights, Md.

You might not remember that incident, but I'm sure Cheye Calvo does. He was the mayor of Berwyn Heights at the time.

The town is located in Prince George's County, the overwhelmingly Democratic, liberal one. But Prince George's County being overwhelmingly liberal and Democratic didn't help Calvo the day members of Prince George's County Sheriff's Office made a raid on his home, looking for marijuana.

It didn't help Calvo's mother-in-law, who ended up lying face down while law enforcement officials searched the home.

And it sure as heck didn't help Calvo's two black Labrador retrievers, who were shot to death after a SWAT team barged into the Calvo abode.

Marijuana was recovered, but the Calvos were completely innocent. It transpired that two miscreants came up with a scheme to have a stash of marijuana delivered to a certain address.

One of the miscreants would then retrieve the marijuana, unbeknown to the people who lived at the address.

So the Calvos were terrorized and their dogs killed for someone else's crime. After the incident occurred, there were all kinds of questions raised. One of them was this:

Was it necessary for a SWAT team to kick in the door of the Calvo home and kill two dogs? Couldn't the search of the home for the illegal drugs have been made after law enforcement officers knocked on the door, as a Supreme Court ruling said should be the standard?

I called law enforcement officials in Prince George's County back in 2008 and asked precisely that question. I was told the matter was "under investigation."

Those in the journalism profession know that when law enforcement types tell us something is "under investigation," what they really mean is this: We aren't going to tell you, ever, and have no intention of doing so.

What was the result of the raid on the Calvo home? Some marijuana was indeed recovered. But you can bet that everyone in Berwyn Heights, Prince George's County, the state of Maryland and the entire USA who wanted to smoke a joint that night, smoked a joint that night.

The same is true of all those states arresting blacks in disproportionate numbers for marijuana possession: No matter how many African Americans are locked up, everybody wanting to smoke a joint will smoke a joint.

Who's really winning the war on drugs?

Washington Examiner Columnist Gregory Kane is a Pulitzer-nominated news and opinion journalist who has covered people and politics from Baltimore to the Sudan.