The concept of constitutionalism refers to a political system governed by a constitution that establishes limited government and the rule of law, in contrast to arbitrary, despotic, authoritarian, or totalitarian rule.

A country’s constitution outlines the fundamental structure of its political system, delineating how its citizens are to be governed. 

The Constitution defines the primary organs of the state—the legislature, the executive, and the judiciary—while detailing their powers, outlining their responsibilities, and regulating their interactions with one another and with the people. Consequently, constitutional governance must inherently be democratic.

Furthermore, constitutionalism is closely associated with a written constitution, as a written document is designed to clearly define and restrict the powers and functions of the various branches of government, thereby ensuring that any government operating under such a constitution is, by necessity, a limited one.

However, it is certainly possible for some countries to possess written constitutions that do not embody democratic principles. In such cases, it can be argued that they have constitutions but lack true constitutionalism. 

Conversely, there are examples of nations without a written constitution that still uphold democracy and constitutionalism, with Israel and the United Kingdom being notable instances.

In this broader sense, constitutionalism embodies the idea that government should be restrained in its powers and that its legitimacy hinges on adherence to these limitations.