Jimmy Higgins said:
Any and every private business should be compelled to provide services to any person, if they provide that service at all.
Here's my take. Any for-profit business requiring a government license to operate and trade with the general public ought to be required by such license to trade with the general public, in general with a few principled exceptions in mind. While they ought not ever discriminate, precisely what discrimination means and what could possibly override it are questions.
So, for example, some idiot believes his religion means he needs to commit suicide inside bakeries to get to the afterlife. A baker locks the door upon seeing the idiot come near the bakery. I know it's a trivial example, but it's there to demonstrate a point that there is something principled at play. Is it that there is a natural value to human life and a store employee can thus stop imminent harm? Maybe?
Someone brought up Nazis. What about a guy with a swastika tattoo going to get a haircut? Should the barber refuse because he or she is offended by the tattoo? Personally, I say no. However, if the barber has some additional reason beyond the tattoo to believe imminent harm is going to happen, I think it's a different story. On the other hand, if I have a Nazi cook working at my restaurant, and I serve diverse clientelle, I think on the grounds I don't want him or her poisoning minorities, it's okay to fire him/her or never to have hired them in the first place.
As I said in another thread, personally, I think it's okay to not hire a pedophile to work at a daycare facility, too. Last time I brought this up, one person started claiming I was talking about a child molester, but I wasn't. A pedophile is merely someone who has attraction to children and might not act on it. However, it creates a risk of harm with significant non-zero probability for that person to work there. Is it really discrimination? Maybe. Let's say they are actually a member of a religious cult who believes in teen marriage, I'd not want them working in a school. Fuck their religion. The same as if they were a member of NAMBLA, I'd be against them being a Boy Scout leader or a priest. Technically, it's discriminating against beliefs or it could be maybe sometimes, but the essential part is it is more about stopping significant harm to others.
So back to this issue of stopping a trans person from being a customer because they are acting like a trans person might, i.e. want a celebration cake. James Madison claims that the baker shouldn't have to make the cake because it offends his religion. I don't think our country's laws should work that way. Now, if on the other hand, someone appealed to the issue of harm and said that the baker didn't want the person to harm themselves by continuing further in actualizing a trans direction, that might be a slightly different question. The mere cake doesn't do much to cause this theoretical harm, though, and the basis for the claim is religious and counterfactual. So, I don't think it has much of a basis to the principled exception I listed. Furthermore, I also happen to agree with Jarhyn's point that I saw somewhere somewhen, maybe not even in this thread--don't remember, that this allowance of discrimination creates a second-class citizen or caste and so in the case of trans people, making them into a low caste is actually harmful to them.
I will add finally, I do not think that for-profit businesses government-licensed to trade with the general public are religious institutions or religiously free entities where they can discriminate using religious ideas as the fundamental reason to discriminate. I think that there are other entities and institutions where the law maybe should tolerate this kind of thing:
1. people's personal lives
2. inclusion in a religious organization
3. inclusion in religious rites
4. a minor side hustle where the person making money is not government-licensed to trade with the general public, has a very small circle of clientele, and declares their income on taxes using some legally valid, miscellaneous itemization of income
My two cents.