How does the basic structure doctrine protect the Constitution of India from major changes?

The basic structure doctrine is a landmark legal principle established by the Supreme Court of India in the 1973 case Kesavananda Bharati v. State of Kerala. It serves as a vital check on the legislative power of the Parliament of India to amend the Constitution.123

While Article 368 grants Parliament the authority to amend the Constitution, the basic structure doctrine dictates that this power is not absolute. The judiciary maintains that the legislature cannot use its amendment power to alter, damage, or abrogate the "basic features" or fundamental principles that define the Constitution's identity.34

Key features protected under this doctrine include:
* The supremacy of the Constitution23
* The rule of law34
* The separation of powers23
* The ideals enshrined in the Preamble3
* Judicial review3
* Secularism34

By reserving the right to strike down any constitutional amendment that violates these core principles, the Supreme Court ensures that the democratic and foundational character of the Indian state remains intact, preventing the Constitution from being fundamentally undermined by transient political majorities.13