“If you sell cakes (Sing), or floral arrangements (Design dresses), you sell to all buyers (Even Donald Trump, the KKK or a Nazi).”
Is that what you meant? I don’t particularly want to force anyone to provide a service to the KKK or Donald Trump if they don’t want to. Of course it would be wrong to prevent Donald Trump or a KKK member from attending a public concert or from wearing a dress they purchased that you happened to design. But should you have to design a specific dress at his request or perform specifically for him at a function of his choosing just because that is your business?