Since people are (naturally) tieing this to Arizona, I'll explain what caused me to think about this in a very generalized way...but I'd like to actually try to keep the discussion on the hypothetical as opposed to becoming another topic fully focused on Arizona (since there's already dozens of those on it).
Something I read today put forward an interesting notion to me regarding some things happening in Arizona (which I'm admittedly not very well versed on). Essentially, pondering the difference between refusing service to a GAY person for being gay because you have a religious issue with it...and refusing service to an EVENT because it's something you have a religious issues with.
Essentially, that there's a bit of a grey area between discriminating against a person for their orientation, and discriminating against an event or action. And because this is such a wedge issue, and like all wedge issues both sides get deeply entrenched and are afraid of any middle ground for fear of losing an inch, that grey area doesn't really get talked about.
That's kind of what led me to this notion.
Undoubtably, if someone walked into a shop and wants to buy some BBQ something and they went "No, I don't sell to white people" that'd be a problem.
And undoubtably, if someone walked into a shop and wants to buy catering services for an event celebrating Charley Mansen and they went "No, I don't want to sell my services to such an event" that there'd probably not be a problem.
HOWEVER...I do think you get into a grey area when you're talking about an event that's tied to a protected status. On one hand, the Business Owner has rights as to what he does with his time and energy and what things his business's name and product will be attached to. On the other hand, the basis for his disagreement is tied in some fashion or degree to the protected class.
It's a sticky issue that I think is missed out on a significant and legitimate discussion because discrimination issues are such an emotional wedge in nature that people are afraid of even exploring.
As it comes to Arizona...do I think a person should be able to discriminate against a customer because they're gay and that's against their religion? No. Do I think they should be able to discriminate against an event because the events purpose is against their religion? I have a bit harder time coming down definitively on that one.
For my example....
Black business owner refuses to sell his BBQ to a a white guy. Problem.
Black business owner refuses to cater a motorcycle rally of a white guy because he has an issue with white people. Problem.
Black business owner refuses to cater a motorcycle rally of a white guy because he has an issue with motorcycles after his son died on one? No problem.
Black business owner refuses to cater a white power rally of a white guy because he has an issue with white power rallys? A lot harder for me to say "problem".