Colorado and many other states legalize weed.
I wonder, just like some states in the United States can legalize weed, can some cities in those states decide to legalize other drugs too?
Regional Marihuana legalization in the United States is a rather fragile legislative construct. According to federal law, Marihuana is still considered a Schedule I substance (the most regulated of five levels) under the controlled substances act. Why it got classified like that and whether or not that classification still makes sense from a medical or political perspective is a different question, but that's how it is.
State and municipal laws which legalize Marihuana are basically a promise that the local law enforcement organizations will not enforce that federal law. And the federal law enforcement organizations like DEA and FBI generally do not interfere with this in order to avoid a conflict between state rights vs. federal rights.
The US legal code doesn't have any laws which apply to Marihuana in particular (as far as I know, IANAL and it's hard to prove a negative in a legal code which fills a whole bookshelf). The substance is covered by the Controlled Substances Act as one of a very large range of substances. So there is no legal reason why the legislative processes which lead to a de-facto legalization of Marihuana could not also be repurposed for different substances, if there would be the political will to do so.
The biggest obstacle is that it is impossible for states to change the federal import or interstate commerce laws, so any substances which are infeasible to produce locally and thus must be imported from other states or even from outside the US would require a change to federal law in order to be made available.
I just want to add that the city of Denver voted to decriminalize magic mushrooms:
Denver will become the first US city to effectively decriminalize mushrooms containing the psychedelic psilocybin, also known as “magic mushrooms.”
So the answer is, yes. Cities can move toward legalization.
It is still not legalization but it's close.