Which law prevails in the event of a conflict between laws?

The reason federal law made in pursuance of the Constitution prevails in the event of a conflict between laws is rooted in the Supremacy Clause of the U.S. Constitution, found in Article VI, Clause 2. This clause establishes that the Constitution, and the laws made pursuant to it, take precedence over any conflicting state laws. It essentially means that when state law and federal law collide, federal law is the authority that must be followed, as long as that federal law is enacted in accordance with the powers granted by the Constitution.

This principle ensures a uniform legal framework across the nation, thereby providing consistency and stability in governance. It prevents states from enacting laws that could undermine federal laws intended to be applied uniformly across the United States, effectively maintaining federal supremacy in the legal hierarchy.

International treaties, while significant, can also be subject to the same supremacy principle, but they must be made in line with the Constitution and federal law to be considered authoritative. Similarly, common law may play an essential role in the legal system but does not carry the same weight as statutes derived from the Constitution and federal law. Each of these alternatives could operate within their own spheres but cannot override the supremacy of the federal law established through the Constitution.