While media attention remains fixed on Donald Trump, focusing too intently on the president obscures the profound role played by the institution of the presidency and the stress test it faces.

The presidency was constitutionally created to be empowered, but is restrained by the legislative and judicial branches of government. It has accumulated greater powers over time, but institutional and normative checks have remained in place.

Five factors determine the outward limits of a president’s power within this constitutional framework: the circumstances in which they came into and occupy office; the president’s political standing and popularity; the degree of friction between the different branches of government and between the states and national government; the president’s ability to control the bureaucracy; and the president himself.

How these factors interact determines the shape and the impact of a president’s term.