The baker must sell anything in his store open to the public. He is not required to fill a custom order, however.
This is precisely the same as it is in all other disciplines. If a neonazi walks into Lowe’s to buy a hammer for building the stage of their next gathering, he cannot be refused service. If he then attempts to hire Bob Dylan to play at said gathering there is no legal requirement for Bob Dylan to show up because that is a custom service provided outside of the scope of normal offerings. Or even easier, the Lowe’s staff is not required to provide a custom hammer with a swastica on it.
If you open a store for the general public you must provide basic services to all, no exceptions. You are never and can never be required to provide custom services which require any amount of additional effort beyond agreeing to sell.
Being a neonazi is a conscious choice, one's sexuality is not. Find a new example to justify this already! I have heard that countless times and it is never even close to resembling the real issue at hand.
