Now that you mention it, let’s just take a look at the 1964 Civil Rights Act, shall we? Let’s take a look at the law that says no, actually, you may not discriminate or segregate on the ground of race, color, religion, or national origin. It does not say “sexual orientation” in that short list, nor does it say “gender.” Both should be added. But the fundamental point is clear: you don’t get to discriminate or segregate for bad reasons.
Title II is INJUNCTIVE RELIEF AGAINST DISCRIMINATION IN PLACES OF .PUBLIC ACCOMMODATION.
SEC. 201. (a) All persons shall be entitled to the full and equal enjoyment of the goods, services, facilities, and privileges, advantages, and accommodations of any place of public accommodation, as defined in this section, without discrimination or segregation on the ground of race, color, religion, or national origin.
(b) Each of the following establishments which serves the public is a place of public accommodation within the meaning of this title if its operations affect commerce, or if discrimination or segregation by it is supported by State action:
(1) any inn, hotel, motel, or other establishment which provides lodging to transient guests, other than an establishment located within a building which contains not more than five rooms for rent or hire and which is actually occupied by the proprietor of such establishment as his residence;
(2) any restaurant, cafeteria, lunchroom, lunch counter, soda fountain, or other facility principally engaged in selling food for consumption on the premises, including, but not limited to, any such facility located on the premises of any retail establishment; or any gasoline station;
(3) any motion picture house, theater, concert hall, sports arena, stadium or other place of exhibition or entertainment;
And so on into the fine print. It’s not an exhaustive list, certainly, but perhaps it didn’t need to be, or perhaps that was all they could do in 1964. At any rate we can see what the basic principle is. You can’t just make people get out because you dislike their race or ethnicity. You would think in 50 years that principle could have sunk in, even into religious bigots in Arizona and Idaho and Indiana.