Professor Volokh writes about his article Deterring Speech: When Is It “McCarthyism”? When Is It Proper? dealing with when economic retaliation against unpopular speech is justified. When the Dixie Chicks announced they were ashamed that President Bush is from Texas some music stations stopped playing their music. MCI stopped using Danny Glover in its commercials apparently because he opposed the Iraq war and defended Fidel Castro. Susan Sarandon, Tim Robbins, and Sean Penn all experieced backlashes for similar unpopluar positions.

While I think it’s inappropriate (and possibly illegal) in general for employers to discriminate on a political basis, entertainment warrants an exception. As Volokh explains:

Entertainers are valued speakers because people like them. Danny Glover makes a good pitchman for MCI because people feel good about him: If MCI simply wanted someone who could act well in its commercials, it could have hired a nameless actor for much less. Susan Sarandon was invited to speak to the United Way because people want to hear the well-liked movie star Susan Sarandon, not because Sarandon is a national expert on women in volunteerism. People go to movies largely because they like the stars’ work, but also because they like the stars or at least like the image that the stars project; the same is true for musicians. That’s a big part of why entertainers have publicists.

When people stop liking you, whether because they think that you’re rude, vulgar, or foolish, your value as a speaker or pitchman falls. People are less likely to want to hear you or buy products that you promote. Those who hire you, invite you, or play your music might understandably switch to someone who alienates fewer audience members. What you gain from your sex appeal, coolness, or association with worthy causes, you lose from what people see as your rudeness, folly, hostility to projects they support, or association with causes they dislike. Tolerance demands that people neither beat you up for your views nor throw you in jail for them. But it doesn’t demand that people continue to like you—and if they don’t like you, then you won’t be as effective a promoter.