At the risk of exposing just how much I am not a lawyer, doesn't that decision rely on the interpretation that the farmer's activities did have a plausible effect on the wider market? Wouldn't that be a tougher sell in the case of cannabis, where there is no national market?
> remains precedent
The current Supreme Court really seems willing to toss aside precedent. I wonder what direction they'd go on this issue.
In the case of cannabis, these are literal businesses engaging in the act of buying and selling. Illinois and probably other states differentiate the amount that can be sold to a customer depending on whether or not they are residents or from a different state.
The notion of national market versus not is a red herring; markets are concepts, not tangible things, and the concept exists independent of the government itself. Making something illegal doesn't stop the sale of it, otherwise there would be no point in the DEA existing.
As for the supreme court, one can hope.