Ronald Reagan

 served as the President of the United States. He had been an actor and the Governor of California prior to his presidency. On 30 March 1981, he was the victim of an assassination attempt by John Hinckley Jr. He received a bullet in his lung. (PROSE: The Assassin's Story)

According to the Eighth Doctor, he was the direct successor to Jimmy Carter. (PROSE: Interference - Book One) His indirect successor from the 1990s, Tom Dering, once speculated that either he or Carter must have secretly constructed Station Nine. (PROSE: Option Lock)