Actually, in real life, the feds have given up on this, they are leaving the states with Medical MJ laws alone. In CA alone, if you have a medical MJ prescription you can carry about as much as you want around with you. I know one guy that has bags full of it he gets on his prescription. I don't use it but the feds have decided it can't enforce in a state that has such laws.
The SCOTUS was wrong to rule like that, BTW. Just as they would be wrong to rule that States don't have the right to ignore fed laws if they keep their firearms that are made, sold solely, in their states free from federal interference. The interstate commerce BS is just that, BS.
Like when the Feds gave up on forced busing.