Public laws are legal axioms that govern the overseeing of the exercise of power by a public institution such as a court. If any public institution makes a decision or passes a law that is contrary to any public law, in other words it is unconstitutional, the legality of that decision may be questioned. Courts were granted the authority to inquire into the legality of any law passed by the government and at times even to void them and declare them unconstitutional.
The power of the courts to review any passed law is known as judicial review. Although, in general, it is the U.S. Supreme Court that undertakes the review, the power and authority to conduct a judicial review is also granted to state and federal courts. The power of judicial review has been inferred, in part, from the U.S Constitution in Article VI, Clause 2 ( called the supremacy clause). It basically states that state laws may not be in violation of the U.S. Constitution and the state courts, through judicial review, have the right to declare unconstitutional any laws that are in violation of the constitution.
Through this process, courts can decide whether a state law is constitutional or not, and their decision is based on their interpretation of that law and whether it is contrary to the U.S. Constitution or sometimes the state constitution. The fact that the courts can rule on the constitutionality of state laws is clearly outlined in the supremacy clause of the constitution; the question that remained unresolved was whether the courts had the same right when the law was enacted by the Congress of the United States. Did the courts have the same power and did judicial review pertain to congressional acts? The answer came in 1803, in the case of Marbury v. Madison. The U.S. Supreme Court handed down a ruling that gave the federal courts the mandate to review congressional laws and to declare them unconstitutional. The Marbury case was the first case where the court ruled that an act of congress was not legal. It was the first time in the history of the United States that the process of judicial review was utilized to invalidate a congressional law.
After the Marbury case, when the court asserted its power using judicial review, it did not void any federal laws for the following 50 years. The next time it exercised the power and declared a federal law unconstitutional was in 1857 in the Dred Scott v. Sandford case. The court did, however, exercise its judicial review power in other situations and declared state laws unconstitutional. That occurred in 1810 in the Fletcher v. Peck case.
There were cases where state courts declared the unconstitutionality of laws and took the position that their decisions were final and that the Supreme Court had no authority to review or go against their decisions. They claimed that the Constitution did not grant the Supreme Court the authority to second-guess the decisions of state courts. These state courts were basically saying that the principle of judicial review did not allow for the federal courts to review state court opinions.
After the Civil War, and the passage of the Fourteenth Amendment, which became known as the equal protection clause, the Supreme Court became concerned that the federal government might assert too much power over the various state governments and the rights of individuals. It therefore applied its power of judicial review and struck down the civil rights laws that were designed to limit racial discrimination in the former Confederate states. The Supreme Court used the rule of judicial review very aggressively and began striking down laws indiscriminately. In 1890, the court became involved in a political battle when it struck down a state law that was going to regulate business. In that same year, in the Milwaukee & St. Paul Railroad Co. v. Minnesota case, the court struck down a state law that dictated railroad rates. The court enforced the doctrine know as Substantive Due Process which invalidated any state law that tried to regulate business.
Although the courts have the right of judicial review, it may not be abused and is subject to judicial self-restraint. The Supreme Court will therefore only hear such cases where the parties are arguing for valuable legal rights.