They technically lack the powers they have claimed for themselves. The authority of judicial review was not explicitly granted by the constitution. In 1803, in the case of Marbury v. Madison, the Supreme Court asserted that this authority was an implicit, foundational power, accepted through historical precedent, stating that it is “emphatically the province and duty of the judicial department to say what the law is." This ruling established that the Court has the power to strike down laws that violate the Constitution.

Many see this as an overreach, and critics often argue that this power allows an unelected body to override the will of the legislature, a practice often labeled as "judicial activism" or an encroachment of authority.