The Basic Structure Doctrine, evolved in the landmark Kesavananda Bharati v. State of Kerala (1973) case, limits Parliament’s power to amend the Constitution under Article 368. It ensures that the essential features of the Constitution — such as democracy, rule of law, and judicial review — remain inviolable, thereby preserving its supremacy.

Significance of the Doctrine

1. Guardian of Constitutional Supremacy: It prevents Parliament from converting India’s constitutional democracy into a parliamentary dictatorship by unlimited amendment powers.
2. Balance between Flexibility and Rigidity: Ensures the Constitution evolves through amendments without compromising its core philosophy and fundamental identity.
3. Judicial Safeguard against Majoritarianism: Protects citizens’ rights and democratic institutions from arbitrary or politically motivated constitutional changes.
4. Strengthens Rule of Law: Establishes the judiciary as the final interpreter of the Constitution, maintaining checks and balances among organs of government.

Judicial Interpretation and Expansion

1. 1. Indira Gandhi v. Raj Narain (1975): Free and fair elections and judicial review were held to be part of the basic structure.
   2. Minerva Mills v. Union of India (1980): Emphasized the harmony between Fundamental Rights and Directive Principles as integral to the basic structure.
   3. S.R. Bommai v. Union of India (1994): Federalism, secularism, and democracy reaffirmed as part of the basic structure.
   4. I.R. Coelho v. State of Tamil Nadu (2007): Judicial review cannot be taken away even by placing laws in the Ninth Schedule.

• Recent Judgments:

1. 1. Kuldip Nayar v. Union of India (2006): The Court upheld reforms in the Rajya Sabha elections, clarifying that not every amendment violates the basic structure.
   2. Union of India v. Madras Bar Association (2021): Reiterated judicial independence as part of the basic structure while striking down provisions affecting tribunal autonomy.
   3. Supreme Court Advocates-on-Record Association (NJAC Case, 2015): Struck down the NJAC Act, reinforcing judicial primacy in appointments as a basic feature.

The Basic Structure Doctrine acts as a constitutional sentinel, preserving the soul of the Constitution against transient political impulses. By evolving its contours through successive judgments, the Supreme Court has ensured that constitutional supremacy and democratic ideals remain intact, making this doctrine the cornerstone of India’s constitutional jurisprudence.