I have no desire to smoke marijuana, partly because doing so might drive me back to the cigarette habit I broke two decades ago. I don’t want to be one of those “cool parents” who pretend to be as culturally advanced as their kids. In my case, that’s a ridiculous aspiration anyway.

And I agree with those who call attention to the dangers of excessive indulgence in marijuana and want to encourage people to resist it. Nobody wants us to become a nation of stoners.

Nonetheless, I have come to believe that we should legalize or at least decriminalize marijuana use. The way we enforce marijuana laws is unconscionable. The arrest rates for possession are astoundingly and shamefully different for whites and African Americans. The incongruence between what our statutes require and what Americans actually do cannot be sustained.

The key document in this debate should be a study released in June by the American Civil Liberties Union. It found that marijuana use is comparable across racial lines — 14 percent for African Americans and 12 percent for whites in 2010. But the arrest rates are not. It turns out that “a Black person was 3.73 times more likely to be arrested for marijuana possession than a white person.”

“In the states with the worst disparities,” the report noted, “Blacks were on average over six times more likely to be arrested for marijuana possession than whites. In the worst offending counties across the country, Blacks were over 10, 15, even 30 times more likely to be arrested than white residents of the same county.”

1 of 5 Full Screen Autoplay Close Skip Ad × Where opinion-makers stand on legalizing marijuana View Photos Americans are rapidly changing their views on marijuana legalization, with majorities in polls in recent months saying they support that effort. Here’s how a few opinion leaders stand. Caption Americans are rapidly changing their views on marijuana legalization, with majorities in polls in recent months saying they support that effort. Here’s where a few opinion leaders stand. Ruth Marcus, The Washington Post NO: “On balance, society will not be better off with another legal mind-altering substance. . . . As the American Medical Association concluded in recommending against legalization . . . ‘Heavy cannabis use in adolescence causes persistent impairments in neurocognitive performance and IQ, and use is associated with increased rates of anxiety, mood, and psychotic thought disorders.’ ” Read the column Dayna Smith/For The Washington Post Buy Photo Wait 1 second to continue.

True, we could equalize things by massively diverting police energies to make sure that whites got arrested at the same rate as African Americans, thus adding to the ranks of those with rap sheets. But to offer this “solution” is to show how absurd it is. If we’re not willing to guarantee that a law is enforced with rough equality, doesn’t this tell us something about what we think of it in the first place?

In a recent New York Times column, my friend David Brooks made the classic argument for keeping marijuana illegal. “Laws profoundly mold culture, so what sort of community do we want our laws to nurture?” he asked. “What sort of individuals and behaviors do our governments want to encourage?”

The “law as teacher” thesis is attractive until you start jailing people and creating arrest records that can harm them for many years. And we don’t need to make something illegal to discourage its use, as we have learned in the battle against cigarette smoking.

According to the Centers for Disease Control and Prevention, the proportion of cigarette smokers in our country dropped from 42.4 percent in 1965 to 18 percent in 2012. We have built legal fences around tobacco, using regulations to send the signals Brooks is talking about without making tobacco consumption a crime.

I know Brooks doesn’t approve of the racial disparities in marijuana enforcement, and I’m sure that’s also true of my Post colleague Ruth Marcus , who wrote last week that “widespread legalization is a bad idea.” At the same time, she asserted: “Throwing people in jail for smoking pot is dumb and wasteful.” This second point is entirely right, which is why we need to change our marijuana statutes.

The debate we need is not between the status quo and legalization but between legalizing marijuana for non-medical uses and decriminalizing it. Decriminalization would be a form of public disapproval without all of the contradictions and injustices of our current approach.

Here, our federal system can help us. Colorado and Washington have embarked on their legalization experiments, while more than a dozen states have decriminalized pot by imposing, at most, limited, speeding-ticket-style penalties for possession.

1 of 9 Full Screen Autoplay Close Skip Ad × The next Democratic leaders? View Photos In her first monthly column for The Post, MSNBC host Rachel Maddow names nine politicians who could be the party’s future national faces. Caption In her first monthly column for The Post, MSNBC host Rachel Maddow names nine politicians who could be the party’s future national faces. Sen. Elizabeth Warren of Massachusetts The former Harvard professor’s staunch populism on issues ranging from financial regulation to expanding Social Security has made her a darling of the progressive wing of the Democratic Party. Though she insists she is not running for president in 2016 , many liberals hope she will provide a more progressive alternative to Hillary Clinton. Joshua Roberts/Reuters Buy Photo Wait 1 second to continue.

Decriminalization, Adam Serwer wrote a few years ago in the American Prospect, might avoid the problems created by a wide-open marijuana market. “I’m not sure what a world with a fully commercialized marijuana industry that profits from turning people into potheads looks like,” he said, “but it makes me nervous.” The alternative is to permit a normal market while sharply restricting advertising and other forms of marketing, as we do with cigarettes.

One way or another, public sentiment is moving toward change, and for good reason. A 2013 Pew poll found that 72 percent of Americans agreed that “government efforts to enforce marijuana laws cost more than they are worth.” That’s true, and those costs are far heavier for some of our fellow citizens than for others.

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