A constitutional government definition implies a form of government that acts upon the authoritative document (constitution), which establishes the system of fundamental laws and principles that regulates the structure, functions, and limits of that government.


As such, this type of government is determined by the presence of a constitution that can be seen as a legal instrument. However, it is primarily a set of fixed standards and principles that are generally accepted as the supreme law of the polity and efficiently administers the implementation of political power.

The Constitution of the United States of America is the fundamental law of the United States. Furthermore, it is a source of all government powers that facilitates crucial limitations on the government in order to defend the basic rights of United States citizens.

Within different types of government, the constitution defines this form of polity together with the prevailing norms and laws of a nation and controls the powers and functions of the government.

The core of constitutionalism is the control of authority through its dissemination to several state organs or offices. It is conducted in a manner that each of them is subjected to reciprocal restrictions and obliged to cooperate in developing the will of the state. Notwithstanding that a constitutional government in this regard prospered in England and some other historical systems for the extended period, only recently, it became identified with forms of mass participation in politics. In terms of the modern world, constitutional governments are generally democracies and are regarded as constitutional democracies or constitutional-democratic systems.

The contemporary political systems tend to incorporate constitutionalism and democracy on a common basis in the primacy as they recognize the will of the majority of the nation that results in free elections. The constitutional government in the United States is based upon the doctrine of separation of powers and differentiates between the legislative branch and the executive.