I drive in Denver a lot, at least 3 days a week, and have for more than 6 years.
There has been a big increase in visible homelessness since the legalization of marijuana. Today there are lots of younger beggars, men who look healthy and capable of working.
This is simply another symptom.
You can blame the marijuana for the increase of bums. However, you can also blame Denver’s Road Home bureaucracy and the millions of dollars in local spending to give to the bums everything that they could possibly want. Denver is attracting bums from all over the USA to come to Denver to get all of the free stuff that the local Democrats want to give to them.
I spent the first 34 years of my life in Colorado, leaving in 2003 and never looking back. Homelessness was a big problem back then as well. Twenty years ago I lived in an apartment right on Capitol Hill and bums were everywhere. They ruined Denver's brand-new (at the time) public library with their vagrancy. The worst were the "crust punks" --dirty, young white men from Boulder who would panhandle aggressively on the 16th Street Mall.
Colorado's Front Range suffered a massive population boom during the 1990s that hasn't really stopped. It flipped the state's politics from conservative/libertarian to liberal. Legal marijuana is but a symptom of this, not the cause. Colorado was on the train to Clown World long before they legalized weed.