The reason for refusing to do business with any particular individual, when one is acting in the capacity of proprietor of a business, has up to now been a matter of personal choice, and one which has been relatively inviolate since the founding of this country.
You do not have to do business with anyone you do not want to have any transactions with. Hostility is very much a reason to avoid further contact with the customer, and expelling them from the premises is entirely within the rights of the proprietor.
Try getting smart with the bartender sometime. You would have found yourself outside on your butt on the sidewalk.
Sadly you are wrong, there are a 1000 laws forcing you to do business with people. Gays have been added to the “special” list.
“You do not have to do business with anyone you do not want to have any transactions with.”
Not a legally accurate statement. I suggest reading the Civil Rights Act, and then the state variations. Freedom of association was a valued right until 1965.