An idealist is appointed to the U. S. Senate, discovers corruption, and is nearly expelled based on false charges; but he stays to filibuster.
Senator Joseph Paine (Claude Rains) and newspaper owner Jim Taylor (Edward Arnold) order Gov. Hopper (Guy Kibbee) who to appoint to replace a dead senator; but his children tell him to appoint the boys' hero Jefferson Smith (James Stewart). Paine persuades Taylor, and Smith accepts, praising Paine. On a train Paine tells Smith how his father fought for lost causes. In Washington Smith meets Paine's daughter Susan (Astrid Allwyn). Smith visits monuments. His secretary Clarissa Saunders (Jean Arthur) is sick of politics and rejects a proposal from reporter Diz Moore (Thomas Mitchell). Smith tells the press he wants a national camp for boys, and papers mock him. Paine tells Saunders to keep Smith away from politics and the dam project. Page Richard Jones explains to Smith who people are. Smith takes the oath, sees the papers, and slugs reporters. Moore tells Smith he is a stooge. Smith goes to Paine, who advises him to draft a bill for the boys camp. Smith is nervous before Susan. Saunders explains to him the process for a bill. Smith makes her work at night and shares his ideas. Saunders learns the camp is to be where Paine wants a dam.
In the Senate Smith presents his bill. Boys cheer; but Paine and Chick McGann (Eugene Palette) confer how to sidetrack Smith with Susan. Saunders shows Smith his letters from boys sending coins. Susan calls and asks Smith to escort her. Saunders drinks with Moore and suggests marriage. Saunders tells Smith she is quitting to marry Moore. She shows Smith the bill on the dam. Saunders cries, and Moore takes her home. Smith asks Paine about the dam and the graft of Taylor. McGann tells Taylor, who invites Smith. Paine complains to Taylor but goes along. Taylor tells Smith that Paine has taken his advice for twenty years. Smith goes to Paine, who advises him to compromise his ideals and not speak on the dam bill. In the Senate when Smith speaks, Paine argues that Smith should be disqualified because he owns land there. A committee chaired by Sen. MacPherson (Grant Mitchell) hears the case as Smith is framed. Called to testify, Smith walks out.
Saunders finds Smith crying at the Lincoln Memorial and urges him to do something. Sen. MacPherson brings a resolution to expel Smith. Senate President (Harry Carey) recognizes Smith, who refuses to yield the floor and exposes the influence of Taylor. Smith asks for a week, but senators refuse and walk out. Smith decides to speak in a filibuster. Saunders has Smith call a quorum to get them back. Taylor controls local newspapers and radio to smash Smith. Majority Leader (H. B. Warner) suggests they outlast him. Smith speaks for kindness and reads the Constitution. Moore tells Saunders that news in the state is stifled. She calls Ma Smith (Beulah Bondi), and the boys publish the story. Men confiscate their papers, and police disperse a march. Ma Smith calls Saunders to have Smith stop. A hoarse Smith pleads to end graft. Paine brings in 50,000 telegrams against Smith, who reads some. Smith tells Paine he will fight for the lost cause because of one rule: "Love thy neighbor." Smith collapses. A frantic Paine calls himself unfit for office and says what Smith says is true.
This Capra-directed classic exposes political corruption
in the "land of the free." Unfortunately the film is
still topical in 2001 as popular opinion is shaped by capitalist
interests that control the media and buy the politicians.