"They said they came to hear "folk music" and not "hateful political rhetoric". They claimed that my advertisement for a folk music concert was a mis-representation. They came for music and not politics. "


Magpie's politics are well known, and even for those who disagree with their stance, I would have a hard time calling it "hateful".   The message that they give is one of unity, not division.

Unless you have a set policy that is published in some fashion, I think the rules would be determined by local laws.

One BIG item that you need to consider - you are a "house" concert. That means a private home and unless your organization has some sort of charter in the state of New York, the individual who owns the home is probably the one who would be sued.

Regardless of being right or wrong, you need to consider the potential problems of unwanted attention can bring to your series - and be prepared to deal with it. Some towns do not take kindly to people hosting concerts for pay in a private residence. Would other legal implications arise if this were brought to light in small claims court?    You could win the battle and lose the war.