What makes a President a "great" President?

An analysis of expert rankings of Presidents yields six key factors that are correlated with whether or not a president is considered "great:"
  1. Longer service in office = higher ranking
  2. Service during time of war = higher ranking
  3. Scandal = lower ranking
  4. War hero = higher ranking
  5. Intellectual brilliance = higher ranking
  6. Assasination = higher ranking
Dean K. Simonton. 1987. Why Presidents Succeed: A Political Psychology of Leadership. New Haven, CT: Yale University Press