Travis's efforts to save Iris were influenced by The Searchers and Notes from Underground, but his attempt to assassinate the presidential candidate Palantine was inspired by current events. In 1972, Arthur Bremer tried and failed to assassinate presidential candidate and Governor George C. Wallace. Bremer, a young loner who lived in a rented room, had been following Wallace closely for several weeks. The choreography of his attempted assassination is almost identical to that portrayed in the movie. As Wallace was walking by, Bremer reached into the crowd with a gun and shot at the candidate. Bremer paralyzed Wallace, but security guards prevented him from doing any more damage. Bremer, like Travis, kept a detailed journal, and one of his motivations for trying to kill the candidate was his own failed relationship with a young girl.

Taxi Driver has influenced many subsequent films, but it is more famous for having influenced another would-be assassin, John Hinckley, Jr. Hinkley was obsessed with Taxi Driver,and more specifically with Jodie Foster, who plays Iris. After stalking Foster unsuccessfully, Hinkley decided that assassinating the president would get her attention. He tried and failed to assassinate first Jimmy Carter and then Ronald Reagan, whom he shot but did not kill.