-- the Congressional Act could have been repealed by the people's representatives in Congress. Congressmen are answering to the voters --
Or Congress could have dug in and been the subversive force in perpetuity. There is no perfect system. Any branch can be the problem, as they are today working in cahoots against the people. Do you honestly think the government is answering to the voters?
-- Once a court has interceded however, the resulting harm is very difficult to undo. --
Your hypothetical responsive Congress can impeach and remove the judges.
If the Constitution truly were “above both congress and the court”, then neither the Congress nor the court can be the arbiter of what is or is not Constitutional.
It is significant to remember, I think, that the Constitution was not written by a court. The Constitution was written by a Congress, and questions of “Constitutionality” are well within the ken of Congress.
The legislators in Congress have a duty to understand the limitations placed upon the Federal government and to pass only those laws which are consistent with same. The President has, through the exercise of veto, the ability to hinder, and even thwart, legislative enactments which are not consistent with his or her understanding of the Constitution. And the courts have the power of enforcing against Federal officials the common law protections and writs, as well as applying the longstanding principals of equity. (As expressly limited by the language in Article III)
But should all these fall short of protecting the nation from an overreaching central government.....”[t]he entire remedy is with the people.”