Twain uses political satire throughout the novel, particularly towards the institution of slavery. In the King and Duke episode, he is poking fun at people's gullibility and the dishonesty of our leaders and politicians. The King and Duke are con men and will take whatever they can to satisfy their own needs. They are fake aristocracy who play upon the ignorance of the people along the river. They put their own needs first and don't care about the damage they do to others. They turn in Jim, cheat the Romeo and Juliet audience, and attempt to gain the inheritance of Mary Jane and her sisters'. The King and the Duke could be symbolic of politicians then and today who will lie, cheat, and steal to gain money, power, or position. And, people fall for it. People are persuaded by the fame, culture, or power of those in charge. Throughout his life, Twain wrote about corruption in government and society. He damns mankind in his essay, "The Damned Human Race" when he writes how humans are the lowest form of animal because of their cruelty, weaknesses, and greed. It is a pessimistic look at the human race written after Adventures of Huckleberry Finn. Perhaps Twain was getting revved up to later write "The Damned Human Race." It would be only natural for Twain to satirically make fun of the "high falootin'" royalty and political leaders across the world who lack compassion for their fellow man and support institutions like slavery.