The obligation or duty of a judge sitting in a court of law is to decide on matters based on a fair and impartial perspective with regards to the application of the law. However, there are instances when a judge makes a decision based on his or her own political ideologies or beliefs. When this occurs, it is said that judicial activism has been exercised.
It is necessary that a judge render a decision based on the laws provided by the Constitution, statutes, and other legislation passed. It is also possible that a judge pass judgment based on a legal precedent. These laws are passed by the legislature, which happens to be the Congress in the United States. This duty of Congress to legislate is based on the idea of checks and balances as proposed by a democratic government. Under this idea, it is the duty of the legislature to provide laws, the executive implements laws, and the judiciary settles questions regarding the laws. However, when a judge exercises his or her own personal belief in deciding a judicial matter, he or she is essentially violating the idea of checks and balances. This is because the judge is essentially creating new laws based on his or her own personal values.
Judicial activism is marked by the overstepping of a justice in deciding upon legal matters. This overstepping entails the rendering of a ruling that may differ from what has been stated in the common law, juris prudence, and the intent of the fundamental law of the land.