Apparently, even libertarians have limits. That’s why the latest concern about legalizing marijuana for recreational use is being expressed by people who sell pot for medical reasons.

Operators of medical marijuana dispensaries are afraid that legalized pot would drive down the prices, making their profit margin disappear. (Black market drug dealers probably have the same objection, but they are not making it publicly.)

There is a bill now before the Legislature to ask voters whether they want to make marijuana legal for all adults and tax sales. Pricing is important, because if legal pot were much more expensive than the illegal kind, there would still be a black market. If it were much less expensive, it could disrupt the medical marijuana delivery system, harming dispensaries and patients.

But since all use would still be illegal under federal law, it’s difficult to see very far into the future.

Unless Congress is ready to change the nation’s prohibition against pot use, this part of the debate is just somebody’s pipe dream.