What mechanism allows courts to overturn laws that are deemed unconstitutional?

Judicial review is the mechanism that empowers courts to examine laws and determine their constitutionality. This principle is foundational to the U.S. legal system and was established in the landmark case of Marbury v. Madison in 1803. Under judicial review, if a law is found to conflict with the Constitution, the court has the authority to declare that law null and void. This ensures that legislative and executive actions adhere to constitutional principles and protects individual rights against potential government overreach.

The other mechanisms listed do not provide courts with the power to declare laws unconstitutional. Legislative vetoes, for example, involve the legislative branch expressing disapproval of executive actions but do not involve constitutional questions. Executive orders are directives issued by the President to manage the operation of the federal government and can be subject to judicial review, but by themselves do not allow courts to overturn laws. Constitutional amendments alter the Constitution itself rather than providing a mechanism to review existing laws for constitutionality.