The idea of “sanctuary” has headlined immigration law and policy debates for several years. To date, however, legal scholarship has focused almost exclusively on states and municipalities that limit participation in federal immigration enforcement. Accordingly, doctrinal and theoretical discussion has centered on sanctuary’s constitutional dimensions, with attention to Tenth Amendment and federalism concerns. But, always true, and ever more since the 2016 election, sanctuary has become a diverse phenomenon, incorporating a variety of public and private institutions and organizations. Local agencies, places of worship, employers, school districts, universities, private property owners, and social media groups are increasingly adopting policies that seek to mitigate federal enforcement efforts. This Article is the first to comprehensively describe and theorize these novel and wide-ranging sources of sanctuary. First, it details this breadth of sanctuary policies and institutions, noting their relative efficacy and differing legal justifications. Second, the Article contemplates how these varied sources of sanctuary work in context and in relation to each other. Borrowing from governance theories that emphasize the importance of networked public and private institutions, we argue that, as a practical matter, governance over immigration enforcement is characterized by a decentralized set of actors. This Article argues that this network of public and private institutions and organizations collectively can calibrate federal enforcement policy and instantiate a competing immigration enforcement regime. Ultimately, this emerging set of actors helps decenter the federal government as the sole locus and source of enforcement policy, and urges commentators and policymakers to move beyond federalism and sovereignty in debates over immigration enforcement policy.