Public figures, of course, are subject to parody and satire. Fame brings with it accolades and attention as well as negative reactions, justified or unjustified. At least the famous can defend themselves when they are alive, but once they die their reputation falls into the hands of historians and the speculation of fiction writers.
Often it can be enlightening and very entertaining -- examples abound such as seeing Pablo Picasso, Albert Einstein, and even Elvis Presley meet on stage in Steve Martin's excellent comedy Picasso at the Lapine Agile. Some imaginative authors can take real figures in history and place them in make-believe circumstances that allow the readers to think about issues still facing them today, such as an aged Adolf Hitler in Philip K. Dick's alternate history classic The Man in the High Castle.
Seth Grahame-Smith has managed to write a popular novel in which he mashes the historical cliches associated with President Lincoln with the vampire trend that refuses to release its fangs from the throat of pop culture. Seth Panitch, the playwright responsible for Hell: Paradise Found, has drawn praise from the theater critic at the Los Angeles Times and is already generating some good buzz as it starts its limited run in New York. Taking real names from history and the characteristics associated with them brings a sense of familiarity to audiences, and then if the writer and performers play with those expectations, the results can startle, amaze, fascinate, entice, and sometimes anger those same audiences.
Be careful if you ever become a celebrity. You'll have a tough time controlling what everyone says about you when you're alive, but you'll have an even tougher time once you're dead!