Q. A constitutional government by definition is a (UPSC Prelims 2020)
Answer: limited government
Notes: The correct answer is [D] limited government. The fundamental essence of constitutionalism is the presence of a "limited government," where the powers of the state are defined and restricted by a set of rules or a supreme law (the Constitution).

• Limited Government (Statement D – Correct): A constitutional government is one that operates under the principle of "Constitutionalism." This means the government is not absolute; its power is restricted to protect the rights and liberties of individuals. Even a government with a massive majority cannot overstep the boundaries set by the Constitution.
• Government by Legislature (Statement A – Incorrect): While many constitutional governments have legislatures, this is not the defining characteristic. Some systems (like absolute monarchies with a rubber-stamp assembly) have legislatures but are not "constitutional" in the sense of limiting power.
• Popular Government (Statement B – Incorrect): A "popular" government (one chosen by the people) can still be tyrannical if it does not have constitutional limits. This is often referred to as the "tyranny of the majority."
• Multi-party Government (Statement C – Incorrect): A country can have a single-party system with a constitution (like China) or a multi-party system, but neither defines the core concept of constitutionalism, which is the limitation of authority.

In summary, a Constitution is often called the "Fundamental Law of the Land," and its primary purpose is to define the powers of the various organs of the state while ensuring those powers are not used arbitrarily.