Glossary
Preemption
The legal principle that a higher level of government's law can override or block a lower level's law on the same subject.
In the United States, federal law can preempt, or override, state law where Congress says so, where the two conflict, or where federal rules fully occupy a field. A state law that is preempted cannot be enforced.
Preemption is central to debates about AI regulation because states have passed their own AI laws, and some federal lawmakers and officials want a single national standard instead. Proposals range from blocking state AI laws outright to setting a federal floor that states can exceed.
An executive order cannot by itself preempt state law; that generally requires an act of Congress or a federal regulation authorized by one. Whether a given law is preempted is ultimately decided by courts.
Read more: our explainer