Well if a business can kick Sanders out then a business can kick out anyone who is not part of a protected group. Since gays are not part of a protected group in most states - this means it is perfectly fine for a bakery, pizzeria, or any any other establishment to not serve gays. If the owner does not agree with their lifestyle or opinions - then no service. Just rolling with the precedent.
And the supreme court upheld it this month, so don't cry foul when others do the same.