Analysis of information sources in references of the Wikipedia article "Supremacy Clause" in English language version.
Under the Supremacy Clause, the "supreme Law of the Land" also includes federal statutes enacted by Congress. Within the limits of the powers that Congress gets from other parts of the Constitution, Congress can establish rules of decision that American courts are bound to apply, even if state law purports to supply contrary rules. Congress also has at least some authority to put certain topics wholly off limits to state law, or otherwise to restrict what state law can validly say about those topics. As long as the directives that Congress enacts are indeed authorized by the Constitution, they take priority over both the ordinary laws and the constitution of each individual state.
During the ratification, various Federalists urged that "in pursuance" of the Constitution meant not just conformity with bicameralism and presentment, but otherwise consistent with the entire Constitution. Only such latter statutes were entitled to be treated as supreme over contrary state law. See, for example, Jensen, ed, 2 Documentary History of the Ratification at 517 (cited in note 59) (James Wilson commenting that "in pursuance" meant that a law was otherwise constitutional). Earlier, Wilson had claimed that Congress could not pass any laws restricting the press because such laws would not be in "pursuance" of the Constitution. Id at 455. See also Jonathan Elliot, ed, 4 The Debates in the Several State Conventions on the Adoption of the Federal Constitution 188 (2d ed 1836) (Governor Johnston of North Carolina commenting that every law consistent with the Constitution is "made in Pursuance" of it; those laws inconsistent are not made in Pursuance of it); id at 182 (William Davie commenting to the same effect); id at 28, 178–79 (James Iredell commenting to the same effect); Federalist 33 (Hamilton), in The Federalist 203, 207 (Wesleyan 1961) (Jacob E. Cooke, ed) (claiming that laws that are not pursuant to the Constitution, but instead invade state power, are acts of usurpation).
