It doesn't need to be good. Atlas Shrugged has sold somewhere between 7 million and 8 million copies in the United States. In 2009, the first year of the Tea Party, it sold around 500,000 copies. Themes from the novel, like the question "Who is John Galt?" and the concept of "looters" who subsist on the work of others, were sketched onto Tea Party signs. Members of Congress compared President Obama's policies to the policies of the novel's villains, a flabby crew of lobbyists and lazy businessmen.
(Screenshot via Weigel)