Supremacy of Constitution
The sanction of this document is superior to ordinary laws that parliament legislates and can only be amended through a process defined in the constitution to keep abreast with times by two third majority of both houses and interpretations or rulings of Supreme Court. It is a document which establishes justice, fundamental rights, equality, promotes general welfare, establishes Constitution as the supreme law of the land, creates an executive branch of government, an electoral college, vests all judicial powers in Supreme Court, authorizes levy of income tax etc and enumerates President’s powers as military commander-in-chief and defines his working relationship with PM who is the chief executive, the legislature which legislates and the process for impeachment of President or change in government.
A government that is formed and functions in accordance with constitution is legal, otherwise it becomes unconstitutional, hence illegal. This is what differentiates a constitutional rule from dictatorial rule. If any law is legislated which is in conflict with constitution, it can be struck down by Supreme Court. Since Chief Justice John Marshall’s time the US Supreme Court has changed the Constitution more than the amendment process has, because the constitution vests it with this power.