In the State of Florida, legislators pass laws related to a wide variety of different issues, from regulating commerce to governing relationships between individuals, businesses and family. Federal laws may also exist that regulate the same things that Florida lawmakers have regulated. Preemption dictates that federal law is controlling over state law.
Because of preemption, if the federal government passes a law regulating something and Florida has a contradictory law, federal law will apply instead of the Florida law. Florida and other states may also be precluded from passing laws regulating a specific issue.
For example, the Cigarette Labeling and Advertising Act is a federal law requiring specific warnings on cigarettes. In § 1334 of the Cigarette Labeling and Advertising Act, the law prohibits any statement, other than the statement required by the Act from appearing on cigarette packages. If Florida were to pass a law requiring a different label than the federally-mandated label, federal law would preempt state law. Only the federal law would apply.
1334(b) further clarifies that states are not permitted to impose any requirement or prohibition on advertising or promotion of cigarettes which are labeled in accordance with federal rules. This means Florida is not allowed to pass any law regulating this issue at all.
In order for federal law to preempt state law, Congress must have enacted legislation and the President must have signed the legislation into law. Congress is said to “occupy the field” when it passes a law addressing a specific issue.
Preemption exists because of the Supremacy Clause, which is found within Article VI of the U.S. Constitution and which states that federal law must be the “supreme law of the land.”