That's not the purpose of the Supreme Court.
The purpose of the Supreme Court is to determine if laws passed by Congress (or by States when the laws end up in federal legal territory) are constitutional, and then only if it's been brought up TO the Supreme Court. Congress can't change the Constitution by itself, any Constitutional amendments must be ratified by 3/4 of the States to become law. The idea there being that a slim majority can't go about changing the Constitution at whim.
The problem is, the Supreme Court is appointed by politicians (by the President) and they are often chosen for their adherence to party doctrine. While Judges are supposed to be nonpartisan, in reality they are VERY partisan if the President and Congress are held by the same party when they are nominated and confirmed. With the court packed one way of the other, you get Supreme Court rulings that aren't based on constitutionality but party doctrine.