Cooper v. Aaron was a unanimous decision made by the Supreme Court in 1957. In this case, the Governor of Arkansas was openly resisting a Supreme Court decision made earlier in the case Brown v. Board of Education. Several school districts in Arkansas were attempting to find ways to continue segregation—a policy that was explicitly outlawed in the Brown ruling. Arkansas legislators did this by passing a law that relieved children from mandatory attendance at integrated schools.
When the case came before the Court, it ruled on the side of Aaron, holding that states were bound by the Court’s decisions and therefore had to enforce them, even if they disagreed with the decision. The opinion of the Court held firmly that it was constitutionally impermissible under the Equal Protection Clause of the Fourteenth Amendment to maintain the law (even though the school board had not carried it out), as the law would deprive black students of their equal rights if it had been carried out.
Even more importantly, the Supreme Court pointed out how the U.S. Constitution was the supreme law of the land (as noted by the Supremacy Clause in Article VI of the Constitution), and because the Court had the power of judicial review (established in the case Marbury v. Madison), the precedent established in the Brown v. Board of Education case became supreme law and was binding on all states. In summary, this means that all states must follow the precedent established in Brown—even if individual state laws contradict it. The Supreme Court asserted that because public officials had an oath to uphold the Constitution, by ignoring the precedent of Court, these officials would be violating that sacred oath. Even though handling education is a power and responsibility traditionally reserved to the states, they must carry out this duty in a manner that is consistent with the Constitution, the Fourteenth Amendment, and the Supreme Court’s precedent.