Target the successful state-authorized businesses (and key individuals in those businesses) selling pot (and those businesses, and key individuals in them, knowingly providing key services to those pot businesses) using, among other tools, RICO, the Continuing Criminal Enterprise law (popularly known as the “drug kingpin” law, with mandatory 20-year or, for.more successful businesses, life sentences), and the regular drug trafficking laws and the full panoply of civil and criminal forfeiture provisions associated with all of those laws.

A state-licensed industry isn't going to survive when most of the evidence that the feds need to secure major felony convictions—and seize all the assets of the businesses—against operators is available in state licensing and tax records, and a tiny bit more work lets them do the similar things to supporting businesses.

State-legal marijuana regulatory schemes—and businesses participating in them, even at one step removed from.the direct marijuana trade—exist through federal prosecutorial forbearance, and one of the reasons that state-legal marijuana businesses have had so much problem with access to banking and other support services is that there is wide knowledge of this fact and the lack of guarantee that that forbearance will continue indefinitely, with potentially devastating consequence for anyone who participated in that market even while the forbearance was the executive policy.