In 2007, the State of Arizona passed the Legal Arizona Workers Act (LAWA) which required all employers to verify the legal status of all prospective employees. Replicating existing results from the literature, we show that LAWA displaced about 40,000 Mexican-born people from Arizona. About 25% of these displaced persons relocated to New Mexico indicating that LAWA had externalities on adjoining states. This finding underscores a pitfall of having decentralized immigration policy in a federal system.