In this article, we analyze the role of local jurisdictions in regulating United States immigration, focusing on local policy responses to unauthorized migration in Montgomery County, Maryland. Important theoretical questions involve the conditions under which local policy responses, and their bureaucratic implementation, are inclusive or exclusive. Our findings indicate that perceptions of public safety are decisive. Consistent with other research on bureaucratic incorporation, our analysis indicates that bureaucratic practice can precede formal policy-making. Yet, this dynamic is not inherently inclusive, and can instead lead to exclusionary measures in order to protect against perceived threats to public safety.