how does the supremacy clause affect the states
Supremacy Clause The Supremacy Clause of the United States Constitution (Article VI, Clause 2) establishes that the Constitution, federal laws made pursuant to it, and treaties made under its authority, constitute the supreme law of the land.[1] It provides that state courts are bound by the supreme law; in case of conflict between federal and state law, the federal law must be applied. Even state constitutions are subordinate to federal law.[2] In essence, it is a conflict-of-laws rule specifying that certain federal acts take priority over any state acts that conflict with federal law. In this respect, the Supremacy Clause follows the lead of Article XIII of the Articles of Confederation, which provided that "Every State shall abide by the determination of the United States in Congress Assembled, on all questions which by this confederation are submitted to them."[3] A constitutional provision announcing the supremacy of federal law, the Supremacy Clause assumes the underlying priority of federal authority, at least when that authority is expressed in the Constitution itself.[4] No matter what the federal government or the states might wish to do, they have to stay within the boundaries of the Constitution. This makes the Supremacy Clause the cornerstone of the whole American political structure.[5][6]
State supreme court Federal courts may overrule a state court only when there is a federal question, which is to say, a specific issue (such as consistency with the Federal Constitution) that gives rise to federal jurisdiction. Federal appellate review of state supreme court rulings on such matters may be sought by way of a petition for writ of certiorari to the Supreme Court of the United States. As the U.S. Supreme Court recognized in Erie Railroad Co. v. Tompkins (1938), no part of the federal Constitution actually grants federal courts or the federal Congress the power to directly dictate the content of state law (as distinguished from creating altogether separate federal law that in a particular situation may override state law). Clause 1 of Section 2 of Article Three of the United States Constitution describes the scope of federal judicial power, but only extended it to "the Laws of the United States" and not the laws of the several or individual states. It is this silence on that latter issue that gave rise to the American distinction between state and federal common law not found in other English-speaking common law federations like Australia and Canada.