Final answer:
Article VI of the U.S. Constitution features the supremacy clause, asserting the dominance of federal law over state law. The Tenth Amendment is the source of powers reserved for states. These elements define the balance of U.S. federalism.
Step-by-step explanation:
Understanding the Supremacy Clause in the U.S. Constitution
Article VI of the U.S. Constitution contains the supremacy clause. This significant clause asserts that the Constitution, federal laws passed by Congress, and treaties made by the government are collectively the "supreme Law of the Land." Consequently, when federal and state laws conflict, the national government prevails, as national laws and the Constitution outweigh state laws. Notably, the landmark case of McCulloch v. Maryland in 1819 invoked the supremacy clause to assert that states cannot tax a national institution. Additionally, the necessary and proper clause from Article I, Section 8, gives Congress the power to enact laws essential for executing its constitutional duties, which also ties into the supremacy of federal legislation.
The source of powers reserved to the states, as outlined in the question, comes from the Tenth Amendment. Unlike the supremacy clause that emphasizes federal authority, the Tenth Amendment specifies that powers not delegated to the federal government nor prohibited by it to the states are reserved to the states or the people. This amendment highlights the balance of power between state and federal governments.