Legalization started in Colorado with a medical marijuana amendment to our constitution in 2000.

The court later ruled that caregivers could service more than five patients, opening the door for street-level medical marijuana dispensaries similar to what you see now in California.

We had 20,000 patients when the US Department of Justice announced in October 2009 that the enforcement of federal laws around marijuana wasn't going to be a priority in states with medical marijuana systems. That started what we call in Colorado "the green rush." By July 2010, we had 100,000 patients.

The voters passed Amendment 64, our recreational marijuana provision, in 2012. It allows for the possession, cultivation, and use of marijuana for recreational purposes by anyone over 21.

Adults are allowed to possess up to an ounce, although nonresidents can purchase no more than a quarter ounce in a single transaction. We've issued 16,000 licenses for folks working in the industry, 2,200 marijuana business licenses, and 16 licenses for laboratories that test marijuana potency and contamination.

Our No. 1 public safety problem is the banking challenge, which stems from the fact that marijuana is still illegal under federal law. A Colorado marijuana grower or a dispensary is functionally identical to any other business—but, because of federal money-laundering laws, it can't access traditional banking services. Because there are massive sums of cash in some of these businesses, the fear is that we're moments away from a robbery or a shooting. We haven't seen this yet, but creating progressive public policy involves anticipating what could happen.

We're the first folks in the world to try this, and we're only a year and a half in, so there's a lot we don't know about how this will impact public health and public safety. We're working to create an infrastructure that allows us to collect this data.

Proponents of marijuana legalization will say, "Do this for the tax revenue," but we've learned that you don't legalize marijuana to make money. There's a 2.9 percent regular sales tax and special 10 percent sales tax on recreational marijuana. There's also a 15 percent excise tax on marijuana flower that's imposed when it's transferred from where it was grown to wherever it's going to be sold or manufactured into an edible product.

Since recreational sales began, we've brought in $79 million in tax revenue (through February). But marijuana revenues are not building roads or going to our general fund beyond what's mandated by the constitution. They're going to hire school nurses to talk to kids about marijuana, to train law enforcement to recognize drugged drivers, to public education campaigns on safe, responsible use.

Marijuana should pay its own way. You don't legalize because it will solve your state's fiscal challenges. You do it because you think it might be an enlightened alternative
to the war on drugs.