In the media drama over the minimum wage, businesses are typically cast as the villains for claiming they can’t afford to pay higher wages to low-skill workers. But a new plot twist is making it harder to tell this liberal tale. In the theater community of Los Angeles of all places, there’s a rebellion against mandated pay hikes. And the resistance isn’t coming from management but from workers upset with their union’s effort to dictate higher pay.

On Saturday in federal court in Los Angeles, a group of actors and other workers...