““the National Program Office called the Presidential Successor Support System, or PS3 for short. The five preselected PS3 teams each consisted of veteran officials who could fill almost every top job in government. Under PS3, which traced its roots to the Carter administration and had no clear constitutional grounding, respected former officials like Howard H. Baker Jr., the onetime Senate Republican leader, former CIA director Richard Helms, former United Nations ambassador Jeane J. Kirkpatrick, and former cabinet secretary James Schlesinger””