Final answer:
Judicial review allows the judicial branch to evaluate the constitutionality of actions taken by the executive and legislative branches, as well as state and local governments. The power, established by Marbury v. Madison, serves as a fundamental part of the system of checks and balances within the U.S. government.
Step-by-step explanation:
Judicial review is a crucial mechanism within the U.S. system of government, providing the judicial branch with the authority to examine the actions of the other two branches - the executive and the legislative. It ensures that the executive branch and the legislative branch adhere to the U.S. Constitution. Established by the landmark case Marbury v. Madison in 1803, judicial review is the power of the courts to nullify any legislative or executive actions they deem unconstitutional. This power is a central aspect of the checks and balances system, preventing overreach by government branches and maintaining the rule of law.
Through judicial review, the courts, including the Supreme Court and lower federal courts, can strike down laws or executive actions at both federal and state levels that do not conform to the U.S. Constitution. This process plays a critical role in shaping the application of law across the country. Furthermore, judges must justify their decisions, which are open to scrutiny from various entities, reinforcing the governance system's balance.
While judicial review is mainly associated with federal courts, it also extends to state courts, which can evaluate state legislation against both the U.S. Constitution and state constitutions. Consequently, judicial review serves as a vital check not only against federal legislation and executive action but also against state and local governmental actions.