Haw constitutional courts can be given the power to strike down some proposed amendments that violate core principles of the constitutional order?
In many instances the powers of the Constitutional Court are written into the Constitution itself, or subsidiary legislation. The CC is ultimately the arbiter and safeguard of constitutional rights, so this is well within their scope of power.
To te extent Constitutional Courts are the gatekeepers of constitutional order - the judges of the statutes - any draft law, bill, proposalof an act or statute, including any amendment thereto falls within their scope of power
The Indian Constitution itself endows the Constitutional Courts with the power of judicial review of legislative enactments, those violate the basic structures of the Constitution.
However it is not applicable for proposed amendments.
In a constitutional democracy the Constituion is the supreme law of the land and any law or conduct that is inconsistent with the Constitution or its core values is liable to be struck down. The supremacy of the Constitution simply means that any law or conduct must be consistent with the supreme law of the land. This is indeed the consequence of a constitutional democracy where the Constitution is the supreme law as opposed to the Parliamentary democracy where laws passed by parliament are not susceptible to be tested against the constitution and therefore cannot be reviewed and set aside by a court of law.
The powers/jurisdiction of constitutional courts are stated clearly in the constitutional provisions. It will identify which measures or situations there might be a violation or infringement of the constitution in general either by government institutions or legislations or administration agencies bylaws.
Proposed amendments to primary law or secondary or Constitutional law- are beyond the scope of any judicial review- No violation- No Application of Doctrine of Ultravires-etc..
By the idea that Amendments are a little bit different than the Constitution, mainly when they overtake the original Constitutional limits. And a Constitutional Court does not give itself “the power”. “The power“ was given to it. By the own Constitution.