Because of John Marshall, what type of laws does the Supreme Court review for constitutionality?

Because of John Marshall, the Supreme Court can review the constitutionality of federal laws that allegedly contradict the Constitution of the United States. This arises from the ruling in Marbury v. Madison, written by Chief Justice Marshall.

Explanation:

Marbury v. Madison is the most significant precedent of the Supreme Court, which gave the power to oversee the constitutionality of laws, as well as to protect the human rights and freedoms of citizens guaranteed by the Constitution.

In this matter, the jurisdiction of the Supreme Court is established in cases where there are differing opinions of appellate courts, when a federal law is being evaluated, and especially when a constitutional issue is raised.

In this way, this ruling modified the system of "checks and balances", allowing the federal judiciary to control legislative and executive power in certain cases. This specific power of the judiciary is not enshrined in the Constitution, but has been put into practice through judicial review. It implies the right of courts to declare invalid and to repeal acts of executive and legislative power (both of the President and of Congress) which are considered contrary to the Constitution. The Supreme Court, through judicial review, cannot amend the Constitution, but can only interpret and apply it in a manner it deems appropriate.