When Thompson, a despondent bank cashier, tries to commit suicide in a south of the border dive because he ruined his life with one crazy moment of dishonesty, he is rescued by the bartender, who relates the story of how one crazy moment of honesty caused his fall from governor of a state to bartender. Dan McGinty's climb to electoral glory begins at a soup kitchen where he is recruited by a crooked politician to vote in various precincts under the names of recently deceased voters for the machine-run mayor. Impressed by McGinty's skill in voting thirty-seven times, as well as his lack of scruples, the political boss welcomes him to the party, and McGinty soon rises from extortion man to alderman. To win the post of mayor, McGinty enters into a business arrangement to marry his secretary, Catherine, and thus dons the mantle of respectability by becoming father to her two children. Six months into the marriage, however, the newlyweds fall in love, and McGinty discovers that his new role as family man and the urgings of his wife instill a sense of honor and decency in him. Elected governor, McGinty informs the Boss that he is through with the party, and when the enraged Boss tries to murder the new governor, he is arrested. Meanwhile, the party, learning of the double cross, exposes McGinty's corruption, and as a result, he, too, is thrown in jail. Imprisoned in adjoining cells, the governor and the Boss begin to argue when the Politician, disguised as a guard, breaks them out of jail. After calling his tearful wife to tell her where he has hidden the money for her and the children, McGinty and the others flee the country. After McGinty's story ends, Thompson has a change of heart, and McGinty goes back to tending bar, aided by the Boss and the Politician.