The Dual Presidency Theory (also sometimes referred to as the 'Two Presidencies Thesis') is a theory proposed by the political scientist Aaron Wildavsky during the Cold War. Influenced by the time period of 1946-1964, the Dual Presidency Theory is based on the principle that there are two versions of the American President: one who is concerned with domestic policy and one concerned with foreign policy. Wildavsky makes the claim that Presidents would prefer to focus foremost on foreign policy because he is granted more traditional, constitutional, and statutory authority when compared to his domestic policy powers. Wildavsky argues that presidents have assumed a more active role with regards to foreign policy because they are able to act more quickly than the United States Congress when pursuing foreign policy. Also, a lack of interest groups active in foreign policy allow the president more discretion when making a decision.
However, since Wildavsky's time, the domestic impact of foreign policy has become more pronounced and important, blurring the lines between foreign and domestic affairs. Politics no longer stop at the waters edge because Congress receives more reliable information on foreign affairs. Foreign policy is very much controlled by partisan politics in the United States today. Presidents no longer may take the liberty to assume public support for his foreign policy initiatives and must strive to build and maintain domestic support for them instead.