In my view, the artist v entertainer argument is immaterial. The moment a performer gets up on stage, he/she is going into public domain. Any statement he/she makes thereafter, whether in word, song, gesture or clothing, is public, whether he/she intends it to be or not. And the performer had better be ready to deal with whatever reaction is caused by the statement, all the way from people leaving and demanding their money back to heckling and verbal abuse. Perhaps the performer was in the wrong venue to start with, or addressing the wrong audience for his/her talents and message - tough, they still have to deal with it.

Everyone has the right to believe whatever they want - in private. But the moment they step on the stage and make a public statement of that belief, they take the responsibility for the message they project and the reaction it will cause, whatever that is.