Upon the death of Senator Samuel Foley, Governor Hubert Hopper, after careful deliberation upon listening to the recommendations of his closest confidantes, appoints young Jefferson Smith to fill the vacancy, despite or because of Smith's lack of political experience and thus lack of political know-how. Jeff is the model of patriotism: he recites Lincoln, and is head of the Boy Rangers. Most in the know know that Hopper is the political lackey of corrupt and powerful businessman Jim Taylor. What most do not know is that another of Taylor's political lackeys is the state's senior senator, the well respected Joseph Paine, who has White House aspirations. Opportunistic Hopper knew that, due to a previous attempt, he could not appoint anyone that Taylor recommended, but sees Smith as someone who Paine and thus Taylor can easily manipulate, especially important now as Paine, Taylor and Foley when he was alive had been working behind the political scenes to push through a dam project, all for their own personal gain, buried in a deficiency bill. When Smith arrives in Washington, he is seen as a naive lightweight and a country bumpkin by almost everyone with who he comes into contact, including the Washington press corps, his fellow senators, and even his secretary Clarissa Saunders - known professionally purely as Saunders - whose years working behind the political system, including being in the know about what her previous boss Foley and Paine were and are up to about the dam project, has made her a cynic. How Paine believes he can keep Smith out of trouble is for him to introduce a bill of his own into the house about an issue passionate to him. What Paine is initially unaware about is that what Smith proposes in his bill would place the dam project in jeopardy. Taylor and Paine have to decide how much hardball they will play to make Smith comply or in turn ruin him, while Smith will show if he has what it takes to play with the big boys on the senate floor. Smith may have some unexpected help from someone who has let Washington get the better of her.