"In The Hidden-Hand Presidency : Eisenhower as Leader, Greenstein attributed part of the public's discontent with presidential performance to the conflict built into the Constitution between the president's apolitical and unifying role as chief of state and his partisan and divisive role as head of government. ... Eisenhower was able to bridge the built-in contradictions of the office and provide an effective leadership style. In his analysis of Eisenhower, Greenstein focused on three classes of variables: the personal properties of the man, his leadership strategies, and his organizational style. Eisenhower's political psychology exhibited antithetical qualities in public and private, a duality well suited for adapting to contradictory public expectations. His leadership strategies involved making his job as chief of state readily visible while covertly exercising much of his public leadership. In parallel fashion, his organizational style focused public attention on the formal machinery but left unpublicized his use of informal organization."