If he runs it like a business, there are laws. Just like if you own a restaurant, it's private property, that doesn't mean you're allowed to let the cockroaches run wild all over the place.
so someone can't refuse business to a white nationist or kkk or white supremacist? Trump Supporter? DOH!
Neither one of those groups is included in what SCOTUS has designated as a "protected class". Businesses have a wide range of reasons for refusing service. SCOTUS has ruled that discrimination and refusal to serve protected classes are not included in that range.
so you're ok with discrimination, how fascist of you.
I am in favor of what you are arguing for, the right of a business person to refuse service to customers for many reasons. The line gets drawn when the Supreme Court rules that certain persons or classes of persons need protection against bigoted discrimination.
A group of people can be refused service at a bar if they are wearing gang colors and patches. They are not a protected class and are not being discriminated against because of their religion, race, color, national origin or ancestry, sex, age, physical or mental disability, veterans status or sexual orientation.
Sexual orientation is under challenge.