So-called "sanctuary" laws adopted by U.S. localities have stirred political and legal controversy since their emergence four decades ago. These policies attempt to disentangle local police and city agencies from immigration enforcement, for example by refusing to detain noncitizens in local jails for immigration violations and declining to facilitate transfer of those noncitizens to federal immigration authorities. Such policies have come under renewed scrutiny in recent years. The desirability of sanctuary policies depends on one’s view of the proper level of immigration enforcement in the U.S., and the role that states and localities should play in the deportation of noncitizens. The legitimacy of sanctuary laws depends on one’s interpretation of the proper allocation of power between the federal government and subfederal units like states and localities. Since the mid-2000s, there have been several attempts to undermine local sanctuary policies both at the federal and the state level. Most notably, President Trump made sanctuary jurisdictions the focal point of its domestic enforcement agenda, often claiming that such policies increase crime and public safety threats.
This article provides an overview of the legality of sanctuary cities in the face of these current developments. It will briefly address three basic questions related to the sanctuary movement: (1) What are sanctuary policies? (2) Are sanctuary policies legal, and how have attempts to dismantle sanctuary policies fared?, and (3) What is the future outlook for immigrant sanctuaries in the U.S.?
To understand the sanctuary debate, it is important to understand the context of U.S. federalism, and specifically "immigration federalism", ie., the authority and leeway of subfederal governments to enact immigration-related policies.
Within this division of power, courts and scholars often describe immigration as exclusively a national concern, solely committed to the central government.
Along with significant Presidential involvement, during this extended period of Congressional inaction, states and localities have also stepped in to regulate aspects of immigration. States and localities may enact laws that affect the lives of immigrants, as long as they are not creating their own admissions or removal criteria, or enacting their own enforcement laws.
Within this spectrum, debates over sanctuary policies are the most controversial and contested aspect of state and local involvement. Yet, the term has no fixed or precise legal definition. In fact, it did not originate from governmental policies, but from churches that were trying to provide physical refuge to Central American and Caribbean migrants who became the targets of robust enforcement efforts by the Reagan Administration in the 1980s.
The term "sanctuary city", however, specifically refers to local government ordinances or law enforcement agency practices that disentangle local agencies from immigration enforcement. Regardless of nomenclature, such policies may range from symbolic statements of welcoming, to promises not to share immigration information with federal immigration agents, prohibitions on local police inquiring about immigration status, and laws that require local police to refuse requests by federal immigration authorities to detain noncitizens in local jails. These types of policies may also be enacted at the state level, as California did with a set of "sanctuary state" laws passed over the past several years, culminating in the 2017 California Values Act.
Importantly, sanctuary policies cannot provide immunity or complete protection from immigration enforcement. The city or local police department can only ensure that local officers or agencies will not aid federal authorities. Even in sanctuary jurisdictions, however, federal officials retain the authority to engage in immigration enforcement on their own. For this reason, many advocates and commentators refer to these enactments as "non-cooperation" policies, rather than using the capacious and potentially misleading "sanctuary" label.
Despite their limitations, local non-cooperation policies are highly impactful because federal immigration enforcement schemes have become heavily reliant on help by local authorities over the last few decades. For example, one of the primary ways federal immigration officers discover the names and locations of unauthorized noncitizens is through information they glean from databases populated by local police officers; one of the primary ways federal agents take physical custody of deportable noncitizens is to ask local officers to hold those noncitizens in local jails, and transfer them to federal custody. Thus, by depriving federal authorities of these sources of information and manpower, sanctuary policies force the federal government to internalize the cost of its immigration policies and enforcement practices. In many cases then, while sanctuary policies cannot guarantee absolute protection from deportation, as a practical matter, they reduce the likelihood that federal agents will discover the status or whereabouts of unauthorized noncitizens in the course of their everyday lives and activities.
In recent years, sanctuary cities have come under increasing pressure from the U.S. government to give up their sanctuary practices.
While both the W. Bush and Obama Administrations attempted to tamp down the sanctuary trend, their initiatives stopped short of requiring repeal of sanctuary laws or mandating compliance with federal immigration efforts. Instead, those administrations opted for more subtle interventions, modifying federal administrative agency practices to blunt the effectiveness of local non-cooperation.
These federal attempts to crack down on sanctuary cities, however, largely failed. This failure can be explained by principles, embedded in the U.S. Constitution, which constrain federal authority over subfederal governments. In a series of important cases over the past three decades, the Supreme Court ruled that the Constitution mandates "anti-commandeering", a federalism principle that forbids the national government from conscripting or forcing subfederal governments into administering federal laws.
Seemingly in response to this set of losses, the newest development in sanctuary politics has been the emergence of several state-level anti-sanctuary laws in states like Texas and Florida, with elected officials who favor the national government’s enforcement-heavy policies.
Unlike when a city resists the national government’s demands, a city has no basis, under the U.S. Constitution, to resist the state government’s dictates. While the federal constitution’s anti-commandeering principle forbids national attempts to conscript local police, no such analogous provision exists to prohibit a state from conscripting local officers into enforcing state law. In fact, municipalities are traditionally understood to derive their existence and governing authority from the state, and are subject to state standards.
In sum, immigration federalism in the United States – the leeway for state and local policymaking related to noncitizens and immigration enforcement – is highly contested. The most controversial aspect of immigration federalism is the issue of sanctuary jurisdictions. These policies are generally shielded from federal anti-sanctuary efforts by constitutional principles that govern how power is allocated between federal and subfederal governments. Thus, several hundred sanctuary jurisdictions continue to exist across the United States, mostly in left-leaning jurisdictions, and large cities, which tend to have high immigrant populations. However, more recently, some states, like Texas and Florida, whose officials share the enforcement-minded goals of the national government, have chosen to enact state-level anti-sanctuary policies. Because of the dynamics of state-city relationships, these anti-sanctuary policies are likely capable of eliminating or curtailing sanctuary policies within those states. Still, in other states like California, New York, and Illinois, sanctuary policies are proliferating at both the city and state level. Until Congress is able to enact comprehensive immigration reform – a task that has eluded successive federal governments for a quarter century – this patchwork of resistance against federal immigration policies is likely to continue.