The problem is the fact that marijuana is still classified by the Federal government as either a Schedule 3 or Schedule 1 controlled substance depending on whether it is for licensed medical use or recreational use respectively. Trump in April just had the classification for licensed medical use changed to Schedule 3 to help facilitate further medical research which had not been the case prior where it was flat out Schedule 1. So with individual State laws essentially decriminalizing marijuana in many cases does not offset the Federal government's classification.

The Federal government also regulates firearms while the states can either go with minimum standards set by the Federal government for possession or try to expand firearm restrictions often putting the two at odds - as is the case between Federal and state controlled substance use laws and their application. When the two come together, controlled substances and firearms, expect some disagreement until on the Federal level it can be sorted out.

When does a person's Constitutional right to bear arms come into play when dealing with controlled substances? Where to draw the line between an absolute right to bear arms and diminished capacity to handle those firearms safely in the interests of the public good? These are questions that still must be answered. Right now it does not seem so clear and the language surrounding these issues need more definition and clarity.