What is an "October Surprise?"
The term describes an event that happens just before voters go to the polls in November. It might be a deliberate act designed to influence the election or a random event that seems to favor one candidate over another.
The term came into popular use in 1972 when the administration of President Richard Nixon told the country peace was at hand in the Vietnam war. The announcement was premature. In hindsight, it appeared to be an attempt to strengthen Nixon's lead in the election.
Since then, Americans have been surprised by terrific storms, the release of videotapes, and a stock market crash.