Firstly, the constitution is a written document which clearly defines and limits the power of government.
Secondly, the constitution is a fundamental law and is superior to the ordinary law passed by Congress
Thirdly, the Act of Congress which is contrary to and violation of the fundamental law is void and cannot bind the courts.
Fourthly, the judicial power obligation to uphold the oath, render it necessary for the courts to declare unconstitutional those acts of Congress which contravene the fundamental law.
It must be emphasized in this connection that the courts are not concerned with policy, wisdom or expediency but only with constitutionality of legislation. In the opinion of Supreme Court, “it neither approves, nor condemns any legislative policy.
Its delicate and difficult office is to ascertain and declare whether the legislation is in accordance with, or in contravention of, the provisions of the Constitution and having done that, its duty ends.”
However, the critics have accused the Supreme Court of becoming a non-elective super-legislature. The judgments have wide ranging consequences. Issues of public policy are severely affected by a minority of American society sitting in the judicial branch of government.
Of late, there has been a change and Supreme Court has undergone modernization and there has been a substantial change in its functioning.