The brave clown who speaks the truth and shames the devil is a showbiz tradition, from Charlie Chaplin to Lenny Bruce. The comedian more than any other creative is best-placed to play the role of the cheeky urchin who points out that the Emperor has no clothes. But in recent years, drolls have ceased to be outlaws – and have become lapdogs of the liberal establishment at best and boot-boy bullies of Jews at their very worst.