The 1980 United States presidential election in South Dakota took place on November 4, 1980. All 50 states and The District of Columbia were part of the 1980 United States presidential election. South Dakota voters chose 4 electors to the Electoral College, who voted for President and Vice President. South Dakota was won by former California Governor Ronald Reagan (R) by a 29-point landslide. It is a reliably Republican state, and the last Democratic presidential candidate to carry the state was Lyndon Johnson in his 1964 presidential campaign.