Who is responsible for determining the constitutionality of laws in the United States?

The determination of the constitutionality of laws in the United States is primarily the responsibility of the Supreme Court. This judicial authority stems from the principle of judicial review, which allows the courts to interpret the Constitution and evaluate whether legislative acts or executive actions align with constitutional provisions. Established in the landmark case Marbury v. Madison in 1803, this power enables the Supreme Court to invalidate laws that it finds in conflict with the Constitution.

Judicial review is crucial for maintaining the rule of law and ensuring that no branch of government exceeds its legal authority. While other branches, such as the executive and legislative branches, can influence or propose changes to laws, only the judiciary has the power to interpret the laws relative to the Constitution and assert their validity or invalidity.

The other options represent different branches of government, each with distinct roles; however, they do not hold the authority to make final constitutional determinations. For instance, the President has executive powers, the Senate plays a role in lawmaking and ratifying treaties, and the House of Representatives is involved in initiating legislation and budgetary processes, but none possess the power granted specifically to the Supreme Court regarding constitutional interpretation.