On her first trip to Washington, D.C., journalist Alice Kingsley is given a tour of the Capitol by acerbic newspaper and radio columnist Gilbert Nunnally, who thinks all congressmen are corruptible. She is intrigued by young Newchester, Massachusetts Congressman Joseph T. Gresham and, on Nunnally’s suggestion, decides to write a story about Gresham, hoping to catch him in a scandal. Because Gresham does not speak to the press, Alice plays on his vanity by saying she works for The National Women’s Gazette , which wants a feature on an honest, hardworking congressman. Attracted to Alice, Gresham is tempted and, after confirming her identity by calling her editor, agrees. Unknown to Gresham, the telephone number Alice gave him is actually Nunnally’s residence and he himself pretends to be Alice’s gentlemanly editor. As Alice follows Gresham around Congress, she is exhausted by his schedule and impressed with his hardworking attitude. When Alice surreptitiously learns that he has been speaking with Philip Emery, a lobbyist for a controversial ship building dispersal bill, Nunnally asks her to keep a close watch on Gresham, who opposes it. Nunnally suggests that if Gresham switches sides, against his constituency, it will be because he has been offered a lucrative position in Emery’s law firm. Although Alice later reports that there is “no dirt,” Nunnally insists that she stick with the story for the week. Although she suspects that Gresham and Republican Charles W. Birch may be at odds, Birch is actually a close friend who has been Gresham’s mentor in Congress. When Gresham returns to Newchester to make some speeches, Alice accompanies him, and is impressed by his unpretentiousness and devotion to his elderly aunt, Miss Dee. They spend a romantic evening together, and when they return to Miss Dee’s house, they are met by Peter Kralik, an elderly European immigrant who sadly tells Gresham that after many years in the United States, he took a trip to Europe and, upon returning, could not get a re-entry visa. Because he had to work so hard over the years, he could not attend school to obtain citizenship papers and will soon be deported. The only way he can stay in America is to have his congressman, Gresham, sponsor a special bill for him. Although Gresham is polite, Alice is surprised by his lack of enthusiasm for Kralik. The next day, as Gresham and Alice are boarding their train back to Washington, Kralik again approaches him, giving him paperwork on the case, but is again rebuffed. Back in Washington, Alice and Gresham, who have fallen in love, attend an embassy party. While dancing with Birch, Alice learns that Gresham’s attitudes toward the press stem from a run-in with Nunnally, whom Gresham is suing for libel. After Birch says that the case comes up in two weeks, Alice finds Nunnally and angrily says she is resigning and plans to do a new exposé on Washington, prominently featuring him. Alice then goes to find Gresham and, from a distance, sees him talking with Emery. Not knowing that Emery has given Gresham a stern lecture about wanting re-election more than learning the facts of the dispersement bill, she begins to have doubts. Also unknown to Alice, Gresham has sponsored a bill to prevent Kralik’s deportation. Next morning, after he has had a chance to read through information that Emery has provided on the bill, Gresham tells Alice that “Potomac fever” had made him ignore the nation’s interest in favor of his constituents. Disappointed, Alice goes to Nunnally to say that he was right, even though she has no proof that Gresham has sold his vote. Nunnally then reveals that he has had Gresham followed and late the previous night he was away from his hotel for over three hours, presumably with Emery. The next day, when the bill comes before Gresham’s committee, he argues bitterly with Birch. Although he votes against the bill, it is passed by the committee and sent to the House floor for a vote. When Senate messengers announce that they have passed the bill, Gresham realizes that he must finally take a stand. To Alice’s disappointment, he gives a short speech announcing he now supports the bill. Birch is proud of Gresham’s honesty and the House gives him a standing ovation, after which the bill is passed. When he rushes out of the House chambers, Gresham is confronted by Nunnally, who says that he will not print the story of how he sold his vote if the libel suit is dropped. Gresham answers by punching him in the nose. Soon, Newchester papers condemn Gresham, and his constituents overwhelmingly express their disproval. Depressed, Gresham calls Alice’s hotel, but is told she is out. He then calls the number she gave him for her editor and is crushed to discover that it is really Nunnally’s residence. Meanwhile, as Alice is leaving her hotel, she runs into Kralik, who joyfully tells her that he will not be deported because Gresham sponsored his bill and was even kind enough to meet his train in the middle of the night. Overjoyed that it was Kralik, and not Emery, whom Gresham had seen that night, Alice goes to Gresham, but he rebuffs her. She admits her earlier subterfuge, and says that she now has a new job, but he sends her away. Later, he is encouraged by Aunt Dee and Birch, who advise him to talk with his constituents and tells him that some of the greatest congressmen were once defeated and returned to long and successful careers. Birch then adds that Alice has a new Washington column and wrote a very nice piece about him. After the House Roll Call, Gresham rushes out of the Capitol Building. When he sees Alice, they throw their arms around each other.