CNSNews.com - Sheriff Arpaio's Office Is Only Law Enforcement Agency in U.S. Denied Authority to Enforce Immigration Laws, Says DHS Another member was stating Rhode Island can enforce illegal immigration locally only because it has a DHS Memorandum of Agreement to do so, and he said Arizona should do the same rather than pass their own laws, but that Arizona stubbornly wouldn't do. Wrong. Maricopa County was the only county denied. Arizona's largest county with the largest illegal problem was the only one denied the MOA to enforce illegal immigration. Arizona tried to do it the right way. Feds said F-you Zona. Zona bravely took the lead.