In the politics of the United States, an October surprise is a news event that may influence the outcome of an upcoming November election (particularly one for the presidency), whether deliberately planned or spontaneously occurring. Because the date for national elections (as well as many state and local elections) is in early November, events that take place in October have greater potential to influence the decisions of prospective voters and allow less time to take remedial action; thus, relatively last-minute news stories could either change the course of an election or reinforce the inevitable.[1]
The term "October surprise" was coined by William Casey when he served as campaign manager of Ronald Reagan's 1980 presidential campaign;[2] however, there were October election-upending events that predated the coining of the term.[1][2]