Denver is at the forefront of America’s next drug reform movement — again. Thousands of residents have signed on in an effort to loosen restrictions on psilocybin mushrooms. In three months, a question about decriminalizing the psychedelic drug will appear on the city’s elections ballots alongside the mayoral election and more mundane affairs. The campaigners behind the Decriminalize Denver measure already have made history: This is the first time U.S.