The worst part is that the states are quite happy to help the feds enforce this. E.g. Hawaii has both mandatory gun registration and requires a state-issued license for medical marijuana. And if you happen to have both, well:
It should also be noted that while DEA is instructed by the executive to not go after cannabis users in states where it's legal for recreational use, there's no equivalent directive issued to ATF.
It would be great if the DEA and ATF were a bit more consistent in their enforcement. Joe Rogan smokes pot and has guns, federal agents busting down his studio door and dragging him away in handcuffs (while state ones look on and clap) would do more to move the needle on drug legalization than most anything else.
https://www.leafly.com/news/politics/surrender-your-guns-pol...
It should also be noted that while DEA is instructed by the executive to not go after cannabis users in states where it's legal for recreational use, there's no equivalent directive issued to ATF.