The movement to legalize or at least decriminalize marijuana has grown considerably in recent years in the United States. Denver has become one of the top cities for marijuana reform, and this week, voters in Colorado’s largest city will have a chance to vote on how another drug is regulated: hallucinogenic psilocybin mushrooms.

If approved, Initiative 301 — which is on Tuesday’s ballot in Denver — would not make psilocybin mushrooms fully legal in that city, but would decriminalize them. Initiative 301 is only on the ballot in Denver. It is not a statewide initiative, although it could possibly lead to a statewide initiative at some point if it passes.

Advertisement:

One of the most ardent proponents of psilocybin decriminalization in Denver is Kevin Matthews, campaign manager for the Denver Psilocybin Initiative. According to the Washington Post, Matthews has used psilocybin to fight clinical depression—and the Denver Psilocybin Initiative has raised about $45,000 so far.

The movement to decriminalize psilocybin in Denver has both its supporters and its opponents. Supporters of Initiative 301 range from liberals and progressives to right-wing libertarians. The Libertarian Party has been staunchly opposed to the War on Drugs and pushed for legalization of all drugs, including hard drugs.

Beth McCann, Denver’s district attorney, and Denver Mayor Michael B. Hancock, both Democrats, are among the opponents of Initiative 301.