Copyright and Compelled Speech

In listening to the argument this morning, I thought about the following test that the Court could use. There seemed to be agreement that "artists" cannot be compelled by anti-discrimination laws to produce their art against their deeply held beliefs. But how do you know whether someone is an artist as opposed to an ordinary business, which can be so regulated?

Why isn't the answer "if their work can be copyrighted?" This standard would distinguish, for example, a baker from a photographer. You can't copyright a cake--food is functional. You can, of course, copyright photos.

This line-drawing isn't perfect. I tend to think of a baker as being more artistic than a website designer. But the point is that we should not make these judgments based on our aesthetic views. Copyright provides an objective and well-settled line for these assessments.