They should have installed proper financial support for this business before legalizing the trade, but indeed maybe good news for Bitcoin. But still a hassle for the shopkeeper.
But that would mean changing federal laws.
I'm not from the US so I am not familiar with this state law - federal law system. ...
Try this on. We've had and will continue to have cases where sheriffs (town or county) publicly announce that if any federal agents try to come into their area and arrest for (x, y,z) the sheriff will arrest the federal agent.
X,y,z have most commonly lately been one or another type of firearms law.
But it wouldn't surprise me if it was weed. Just announcing that would make the sheriff immensely popular and in reality, the federal agents would go somewhere else.
But this would not help the banks who are trying to stay in line with regulations.