The Supreme Court has refused to hear an appeal from Christian photographers who were fined and admonished by the New Mexico Supreme Court for declining to work a same-sex ceremony, in what could be a blow to religious business owners...I understand the “artistic expression” argument—and in fact, I’ve been trying to think of a way to word that for quite awhile now.
Elaine Huguenin said she also has a right of artistic expression under the First Amendment that allows her to choose what pictures to take, or refrain from taking.
We as a society have decided that we’re not going to allow businesses to refuse service to customers—we’re long past the days of “no coloreds allowed”. However, there are differences between types of businesses.
If your business sells widgets in a store, you will sell widgets to anyone. That’s what we as a society say is part of the arrangement of getting a license to conduct business.
However, if some rich patron wants to commission a portrait, is the artist required to paint it? Of course the answer is no. If a corporation wants to hire an architectural firm to design a building, is the firm required to design the building? Of course not. Must a photographer photograph a child's birthday party (age discrimination!)? Of course not. The difference in these examples, as opposed to the widget store, is that there is an element of artistic expression.
I’m not willing to go all the way with the artistic expression, though. If the patron wants you to paint a nude and you don’t do nudes, then you don’t paint it. Is a florist an artist, or are they selling flowers? How much individuality, how much creativity, goes into each wedding cake, as opposed to a painting? What is the difference between "I don't do kids' birthday parties" and "I don't do gay weddings"?
When I worked for a small custom computer cable assembly firm, we didn't have to accept every order that came through the door (but we did accept them because we needed the money). When must a business accept business, and when can it decline?
These are, to me, interesting questions worthy of exploration. The New Mexico Supreme Court did a disservice by not fleshing out the limits.