Final answer:
Judicial review is the power of the U.S. judiciary to invalidate laws and actions by the other branches of government if unconstitutional, a key aspect of checks and balances. Established by Marbury v. Madison, it upholds the Supreme Court's ability to check legislative and executive powers.
Step-by-step explanation:
Judicial Review in the U.S. Government's System of Checks and Balances, Judicial review is a pivotal function of the U.S. Supreme Court and lower courts within the governmental system of checks and balances. It is not expressly mentioned in the Constitution but was established by the landmark Supreme Court case, Marbury v. Madison in 1803.
This power enables the judiciary to assess and overturn laws and actions by the legislative and executive branches if deemed unconstitutional. As such, the Supreme Court can ensure that the legislative and executive branches do not exceed their constitutional powers.
Although judicial review is seldom exercised, it holds significant weight. Since its establishment, the Supreme Court has only invalidated a small fraction of national and state laws. However, this check maintains the balance among the branches and affirms the Court's role in safeguarding constitutional governance.
Despite its essential role in the dynamics of federal power, the use of judicial review often sparks discussion and debate, particularly when courts are accused of judicial activism for creating quasi-legislation through their decisions.