The concept of judicial review gives the US Supreme Court the ability to determine the constitutionality of any law made by the legislative branch. This concept is imperative, as it allows the US Supreme Court to get rid of any law that violates an individuals constitutional rights. Along with this, it allows for the Supreme Court to check the power of the legislative and executive branches.
Without this power, Congress and the President could make laws that violate the individuals rights, and there would be no structure to stop them.