Preemption Definition

1) The principle that a federal law supersedes a state law, or a state law supersedes a local law, when both governments have made laws on the same subject. Preemption can be found when:

  • the superseding federal or state law expressly preempts conflicting state or local laws, or
  • the superceding federal or state law is comprehensive and occupies the field, or a conflicting state or local law frustrates the purpose of the superceding law.

2) The right to purchase before others (for example, a preemptive right).