It started with Richard Nixon.

When he publicly launched the war on marijuana 40 years ago, the decision was not grounded in facts or reason. Actually, it was just the opposite.

The president handpicked a national commission in 1971, and tasked it with taking a hard look at the substance. Chaired by Raymond Shafer, the Republican governor of Pennsylvania, it was no left-leaning group. They approached the subject objectively and produced a comprehensive report. Their conclusion? The harms of marijuana are quite limited, and the use of marijuana by adults should not be considered a criminal offense.

Nixon promptly ignored their findings and moved forward with his plan to make marijuana Public Enemy No. 1. Since that time, marijuana prohibition has become an industry, and the actors whose jobs are dependent on that industry are fighting tooth and nail to keep it going.

By and large, they are members of law enforcement, such as the Colorado Drug Investigators Association. This trade group of narcotics officers knows that the 10,000 marijuana arrests that occur in Colorado each year account for more than 60 percent of all drug-related offenses in the state. If marijuana prohibition fizzles out, so do the budgets for enforcing it.

As a result, these individuals who should just be enforcing the law engage in biased public dialogue in order to prevent sensible changes in the law.

They advocate arresting and prosecuting adults for marijuana, even though there is no arguing whether limited law enforcement resources would be better spent combatting violence and other crimes that actually cause harm to others.

Instead of trying to eliminate modern-day Al Capones, these law enforcement officials are actually working to keep them in business. They decry illegal grows by drug cartels in neighborhoods and national forests, yet seem oblivious — intentionally or not — to the fact that regulating the production of marijuana is the only way to eliminate this illicit cultivation.

A vote against Amendment 64 is a vote to keep profits flowing to these drug cartels instead of legitimate Colorado businesses.

Worst of all, these tough men — yes, they are mostly men — prey on parents’ fears about their children in order to continue using your tax dollars to fight an endless battle to prevent adults from using a product proven to be less harmful than the one our president brews in the White House.

On the children issue, they are both wrong and reckless. Any objective examination of the facts demonstrates that marijuana prohibition is the worst possible policy for children. It has created a situation in which underground marijuana is almost universally available to teens, and those teens who inevitably seek it out are often exposed to other, more dangerous drugs.

Moreover, there is now evidence that regulating marijuana might be better for teens in Colorado. Since our state established a tightly regulated legal medical marijuana market in 2009, marijuana use among high school students has dropped 11 percent in the state, according to surveys conducted by the U.S. Centers for Disease Control and Prevention. Nationwide, where marijuana is entirely unregulated, it increased 11 percent.

As a last resort, our opponents try to scare voters and business leaders with unfounded claims that passage of Amendment 64 will affect the workplace, despite the fact that the measure explicitly grants employers the right to maintain all of their current employment policies.

So, what is motivating our opponents? Are they attempting to deceive the public, or are they actually unable to see the problems associated with marijuana prohibition and the benefits of regulation?

Perhaps it is the latter. As author Upton Sinclair once said, “It is difficult to get a man to understand something when his salary depends on his not understanding it.”

But I hope you understand it is time to replace this ineffective and wasteful policy with a more sensible approach.

Please vote “yes” on Amendment 64 to regulate marijuana like alcohol.

Betty Aldworth is advocacy director of the Campaign to Regulate Marijuana Like Alcohol.