You are misinformed.
Presidential Discretion and Policy Change
Discretion in a political setting is the authority to decide whether or not to take policy action, and if so, which action or policy to choose. A variety of policy makers enjoy this kind of discretion, including presidents, federal bureaucrats, teachers, police officers, judges and state governors. Though presidents are typically chief executives whose exercise of discretion has broad influence on policies and other political actors, presidential discretion has mostly escaped systematic empirical investigation.
Presidents derive their discretion from a variety of sources, including explicit grants of authority or useful ambiguities in constitutions, and most importantly, delegation from legislatures. The literature on delegation is vast and spans disciplines, but the stylized process is easy to summarize.
Footnote4 Laws often do not (or cannot) spell out exactly how policy should be carried out. Legislators sometimes lack the necessary time or expertise (for example, Landis
Reference Landis1938). They may prefer generalities to avoid making controversial decisions (Fox and Jordan
Reference Fox and Jordan2011) or because they lack the expertise to develop higher-quality policy. As a result, laws invariably include some imprecision that allows (or even asks) the executive branch to step in (VanSickle-Ward
Reference VanSickle-Ward2014). This process is ubiquitous. According to one recent estimate, more than 99 per cent of all major US laws contain at least some delegation to government agencies (Clouser McCann and Shipan
Reference Clouser McCann and ShipanForthcoming). Problems and controversies arising from this basic fact motivate much research in the legal subfield of administrative law.