Marijuana has become the leading agricultural commodity

Marijuana has become the leading agricultural commodity produced in Massachusetts (recently passing the cranberry). In order to protect this rapidly expanding industry, the Commonwealth passes a fee ($5.00 a pound) that is to be charged to any out-of-state or foreign marijuana grower who imports marijuana into the Commonwealth. The fee goes to the treasury of the Commonwealth.
“Ganga for All” is a Canadian corporation based in Halifax, Nova Scotia, Canada and is a grower of marijuana. The marijuana grown by Ganga for All is very much in demand because of its quality. “Ganga for All” is owned and operated by its sole employee Paul Pothead, who, like many others, has dual U.S. and Canadian citizenship (he lives most of the time in Massachusetts). Paul imports most of his product into Massachusetts and, for the past three years, has been paying the Massachusetts marijuana import fee.
Paul Pothead is told by a friend that the Massachusetts import fee may be illegal. He hires you to be his lawyer (saying: “I think my constitutional rights have been violated man; check it out, Section 10 of Article I prohibits states from imposing a tax or duty on stuff that is imported.”) and tells you that he wants to file suit against the Commonwealth and/or its treasurer or governor in order to recover the amount of money equivalent to the import fees he has paid the Commonwealth over the past three years ($50,000.). He also wants an injunction to prohibit the Commonwealth from enforcing the import fee requirement in the future. He insists on filing the suit in the Massachusetts state court. To quote Paul: “People tell me that suing in the federal court could be a problem, and I don’t want to haul my butt down to Boston. With all the hostile traffic, it’s a bad trip down to that city, man. It could ruin my day. File the case up in Essex County Massachusetts. I’m always bringing my weed down to that county.”
Could you successfully file a Section 1983 lawsuit in the Essex County Massachusetts Superior Court against the Commonwealth, the Treasurer, and the Governor? What problems might you encounter? Please discuss.