Trump’s efforts to force state cooperation on immigration raise pressing questions about the constitutional limits of federal authority.
On the second day of the new Trump administration, the Department of Justice announced that it would investigate state and local officials who refuse to enforce federal immigration policies, reviving a debate over the limits of federal authority.
In a Jan. 20 executive order titled “Protecting the American People Against Invasion,” President Trump directed the secretary of homeland security to authorize state and local law enforcement to function as immigration enforcement “in relation to the investigation, apprehension, or detention of aliens in the United States.” The order also directed the secretary to establish voluntary agreements with state law enforcement agencies that provide for cooperation with federal immigration enforcement, such as “ICE detainers” requiring local police to notify Immigration and Customs Enforcement (ICE) when detaining a migrant and to hold the migrant until ICE assumes custody.
While voluntary cooperation between the federal government and state law enforcement is a well-established practice, efforts by the Trump administration to compel state law enforcement to enforce federal immigration law is a contentious legal issue. At the core of this issue is the anti-commandeering doctrine, a principle established by the Supreme Court that prohibits the federal government from compelling states to administer federal programs. In New York v. United States, the Court ruled that Congress cannot require states to enact or enforce a federal regulatory program. This principle was reaffirmed in Printz v. United States, which struck down a federal law mandating local law enforcement to conduct background checks on gun buyers. These cases have served as the foundation for legal challenges against federal efforts to force state compliance with immigration enforcement.
With the rise of “sanctuary cities”—jurisdictions that limit state and local cooperation with federal immigration enforcement—the issue of state compliance with immigration enforcement has become urgent. Can the federal government investigate, prosecute, or penalize state and local officials who refuse to enforce federal immigration policies? The short answer: Not easily. The Constitution and case law place significant restrictions on the federal government’s ability to conscript states into enforcing federal immigration laws.
Litigation During the First Trump Administration
During the first Trump administration, the federal government repeatedly attempted to penalize state and local governments that refused to align with federal immigration priorities. However, courts consistently affirmed that states’ police powers grant broad discretion in setting law enforcement priorities. These powers refer to a state’s authority to manage local affairs, including how local law enforcement prioritizes public safety, a principle that originates from the inherent sovereignty of the states—found in state constitutions and common law traditions predating the U.S. Constitution. Police powers allow states to regulate the public health, safety, morals, and general welfare of their citizens, as referenced in cases such as the Slaughterhouse Cases and Jacobson v. Massachusetts, which upheld state authority to enact public health measures like regulating slaughterhouses by creating a monopoly to centralize control over slaughterhouses (the Slaughterhouse Cases) and vaccination mandates (Jacobson v. Massachusetts). While immigration enforcement falls primarily under federal jurisdiction, states retain influence over related actions. Courts have emphasized that although federal law establishes the overarching framework, state and local authorities retain latitude to craft policies that reflect local needs and values, drawing a distinction between federal immigration enforcement and local public safety efforts.
These constitutional boundaries have come into sharp focus in legal disputes over specific statutes that attempt to mandate cooperation between state and federal actors. One key battleground in this debate has been 8 U.S.C. § 1373, which illustrates the limits of federal authority to override state and local discretion in immigration enforcement.
Federal vs. State Authority
One of the disputes that has emerged is over federal attempts to compel state and local officials to share immigration-related information. Under 8 U.S.C. § 1373 (and its similar counterpart, 8 U.S.C. § 1644), states are generally prohibited from restricting communication with Immigration and Customs Enforcement. However, despite the Justice Department citing § 1373 as a basis for investigating local officials, precedent has consistently undermined such claims. Local authorities argue that mandatory disclosure disrupts long-standing practices designed to maintain community trust and local control over law enforcement—core components of state police power.
In United States v. California, the U.S. Court of Appeals for the Ninth Circuit rejected the federal government’s argument that § 1373 mandated state and local cooperation, holding that the statute merely provided the option, not the requirement, to assist ICE. The court upheld a California law that barred state and local law enforcement from sharing certain information, such as release dates, with federal immigration authorities. Emphasizing that “[r]efusing to help is not the same as impeding,” the court warned that treating noncooperation as obstruction could enable the federal government to commandeer state resources in violation of the 10th Amendment.
Similarly, in United States v. New Jersey, a district court rejected the federal government’s argument that New Jersey’s Immigrant Trust Directive—prohibiting local jails from providing ICE with detainees’ release dates and requiring that detainees be notified of federal civil immigration enforcement requests—was preempted by § 1373. The court found that the directive did not amount to such “affirmative interference” that would create a preempted “obstacle” under the Supremacy Clause, a clause that establishes that the Constitution, federal laws, and treaties are the supreme laws of the land, thereby trumping conflicting state laws. The ruling relied on the Supreme Court’s holding in Arizona v. United States, which clarified that the Immigration and Nationality Act (INA)—an expansive federal statute governing immigration and citizenship, and establishing the framework for the admission, exclusion, deportation, and naturalization of noncitizens—gives states the option, not the obligation, to assist federal immigration authorities. In doing so, the district court reinforced that under the 10th Amendment’s anti-commandeering principle, New Jersey’s directive fell squarely within its police powers. The U.S. Court of Appeals for the Third Circuit reached the same conclusion in Ocean Cty. Bd. of Comm’rs v. AG of N.J.
The analysis in Arizona v. United States focused on Arizona’s state immigration laws, which were more restrictive than the actions of the federal government in the immigration domain. The Court found that the provisions in question conflicted with the federal immigration framework as outlined in the INA. Although in this case the state wanted to further rather than detract from immigration enforcement, the Court emphasized that federal law preempts state actions in areas where Congress has established a comprehensive regulatory scheme, like the INA. While states may assist federal authorities in certain ways, such cooperation must align with federal law and cannot be unilateral or independent of federal oversight. It further explained that states do not have an obligation to cooperate with federal immigration enforcement but may have the option to do so under certain circumstances.
Federal Funding
One of the first Trump administration’s strategies for enforcing compliance was conditioning federal grant funding on immigration enforcement cooperation. In 2017, Trump issued an executive order, “Enhancing Public Safety in the Interior of the United States,” seeking to disqualify sanctuary cities from receiving federal grants. This triggered a wave of litigation that largely invalidated these efforts, with courts focusing on whether compliance with § 1373 could be a condition of receiving federal funds. In City & Cty. of San Francisco, the Ninth Circuit held that the executive order violated the separation of powers doctrine by claiming for itself Congress’s exclusive spending power.
The U.S. Courts of Appeals for the First, Seventh, and Ninth Circuits all affirmed lower court rulings that the Justice Department exceeded its authority by imposing immigration-related conditions on Edward Byrne Memorial Justice Assistance Grant funds, finding that such conditions violated the separation of powers by infringing on Congress’s authority over federal spending. In contrast, the Second Circuit in New York v. United States Department of Justice upheld certain funding conditions, reasoning that they did not violate the anti-commandeering principle since states could reject the grants if they chose not to comply. This ruling underscored ongoing legal uncertainty. Nevertheless, even where the conditions were upheld, courts acknowledged that states and localities could not be forced to actively participate in enforcement.
On § 1373’s constitutionality, courts reached differing conclusions. The Ninth Circuit held that its ruling in California clarified that § 1373 applies only to immigration status information and did not create a conflict with state law, rendering facial constitutional challenges moot. In contrast, the Seventh Circuit ruled that § 1373 was unconstitutional because it violated anti-commandeering by compelling state and local governments to enforce federal immigration laws without congressional authorization. District courts in Oregon and Pennsylvania reached the same conclusion.
Other Federal Legal Theories Against Sanctuary Cities
Beyond § 1373, the federal government explored alternative legal theories to challenge sanctuary policies, citing 18 U.S.C. § 371 (which criminalizes conspiracies to commit an offense against or defraud the U.S.) and 8 U.S.C. § 1324 (which prohibits knowingly assisting, harboring, or transporting undocumented immigrants to evade enforcement). However, no court has upheld the application of these statutes against sanctuary cities.
Indeed, in Chicago v. Barr, the Seventh Circuit found that conditioning federal funding on compliance with § 1324 exceeded Justice Department authority. Courts generally interpret “harboring” under § 1324 as requiring active efforts to shield an undocumented person from detection, such as providing housing, false documents, or transportation—rather than passive non-cooperation. Similarly, liability under § 371 has typically required active deception or affirmative interference, not mere refusal to cooperate. Courts have thus protected state and local sanctuary policies under the anti-commandeering doctrine, finding that policies declining to share information or honor detainer requests do not meet the standard for obstruction or harboring.
Biden-Era Shifts in Immigration Enforcement
Upon taking office, the Biden administration redirected immigration enforcement priorities away from broad deportations, focusing instead on individuals who posed threats to national security, public safety, or border security. This shift, formalized in Secretary of Homeland Security Alejandro Mayorkas’s 2021 enforcement guidance, reinforced the ability of states and cities to limit cooperation with ICE without federal interference. At the same time, these revised priorities faced legal challenges from states seeking to compel more aggressive enforcement.
The Ninth Circuit reaffirmed its position in City & County of San Francisco v. Garland, holding that its prior ruling in California dispelled any conflict between 8 U.S.C. § 1373 and federal law. Similarly, in McHenry Cty. v. Raoul, the Seventh Circuit upheld an Illinois law prohibiting state agencies and political subdivisions from contracting with the federal government to house immigration detainees. The court reasoned that while Congress required federal authorities to “consider” available facilities before constructing new ones, this did not preempt a state’s decision to make its facilities unavailable. Furthermore, the court held that although the law increased costs in an exclusively federal domain, it did so neutrally and did not violate intergovernmental immunity. While the anti-commandeering doctrine allows states and localities to withhold affirmative assistance from federal immigration enforcement, intergovernmental immunity bars them from obstructing or discriminating against the federal government’s lawful operations and its private partners.
The courts also addressed cases involving state officials accused of obstructing federal immigration enforcement. In United States v. Joseph, a Massachusetts judge and deputy sheriff were accused of allowing an undocumented immigrant with a pending ICE detainer to exit a courthouse through a rear door to avoid federal agents. The defendants appealed, arguing that their prosecution improperly entwined federal authorities in state judicial proceedings, violating principles of federalism and the 10th Amendment. The First Circuit dismissed the appeals as premature. The case was later dropped.
Conversely, in United States v. King County, the Ninth Circuit held that a county executive order restricting ICE flights from using King County International Airport (Boeing Field) violated the doctrine of intergovernmental immunity. The court found that the order effectively regulated the federal government’s method of transporting immigration detainees and unlawfully discriminated against fixed-base operators that contracted with ICE. In the broader context of sanctuary policies and Biden-era enforcement priorities, King County highlights the legal boundary between permissible non-cooperation and impermissible interference.
Even as some sanctuary jurisdictions successfully invoked the anti-commandeering principle to justify non-cooperation with ICE, conservative-led states sought to resist the Biden administration’s more lenient enforcement policies by asserting their own authority—efforts that courts have largely struck down.
In United States v. Texas, the Fifth Circuit struck down a Texas law criminalizing illegal entry, ruling that it conflicted with federal authority over immigration. In a separate case also titled United States v. Texas (599 U.S. 670), the Supreme Court held that Texas and Louisiana lacked standing to challenge federal immigration guidelines. However, the Court suggested that this conclusion might change if the federal government completely abandoned enforcement.
While the Biden administration largely upheld sanctuary jurisdictions’ rights to set policies, legal battles persist over state efforts to assert enforcement authority conflicting with federal priorities.
Immigration Enforcement Under the Second Trump Administration
Under President Trump’s second administration, the federal government has ramped up efforts to enforce immigration laws and challenge sanctuary city policies. The aforementioned executive order, “Protecting the American People Against Invasion,” mandates that the attorney general and the secretary of homeland security evaluate and pursue all lawful actions to ensure that sanctuary jurisdictions are denied access to federal funds. The order further enables these officials to consider criminal and civil actions against jurisdictions whose practices obstruct federal law enforcement.
In response, several sanctuary cities and states have reaffirmed their commitment to protecting undocumented immigrants. For example, Illinois has enacted legislation prohibiting local jurisdictions from cooperating with ICE on deportations. Cities such as Ventura, California, are proposing policies to bolster protections for immigrants and other vulnerable communities. Connecticut Gov. Ned Lamont responded to Trump’s policies by assuring undocumented immigrants in his state that they are “welcome here” and that Connecticut would “honor and protect immigrants and immigrant families in full compliance with the law.”
On the opposite side of the issue, Tennessee’s Republican lawmakers are pushing an immigration bill that would allocate $5.5 million to enhance immigration enforcement, including imposing severe penalties on local officials who support sanctuary policies.
Voluntary Collaboration With Federal Immigration Enforcement: 287(g) Agreements
For states seeking to collaborate with the federal government on immigration enforcement without facing legal challenges, the 287(g) agreements offer an alternative path. Under the INA, ICE may enter into 287(g) agreements with state, local, or private entities. These agreements allow nonfederal officials to perform immigration enforcement tasks on behalf of federal agencies, provided they choose to participate.
In Abriq v. Hall, the court clarified that without a valid, current 287(g) agreement, local law enforcement cannot rely solely on an ICE detainer to make an arrest. Similarly, in Lopez-Aguilar v. Marion County Sheriff’s Dep’t, the U.S. District Court for the Southern District of Indiana confirmed that federal permission to cooperate in immigration enforcement does not compel local officers to act unless expressly authorized. District court decisions like Morales v. Chadbourne and Castaneda v. Cty. of Suffolk reinforce the idea that detention must be backed by probable cause, regardless of whether there is an ICE detainer in place.
Because participation in 287(g) agreements is voluntary, states retain the discretion to collaborate, ensuring local law enforcement operates within the bounds of its traditional police power. This voluntary nature avoids anti-commandeering challenges. Instead of being a fallback for mandatory enforcement, 287(g) agreements can serve as a structured tool, allowing for cooperation with federal enforcement while preserving local discretion.
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The question of whether the federal government can compel state and local authorities to enforce immigration law lies at the heart of tensions between federal supremacy, state sovereignty, and individual rights. Judicial decisions across the Trump and Biden administrations have consistently affirmed that immigration enforcement is a federal responsibility—but one that cannot be delegated by force. The anti-commandeering doctrine and the scope of state police powers together create strong constitutional barriers against mandating state participation, even as voluntary cooperation—such as through 287(g) agreements—remains lawful.
Still, key legal questions remain unresolved. Can Congress design funding conditions that compel state cooperation without violating anti-commandeering limits? And how far can states go in resisting federal enforcement before running afoul of intergovernmental immunity principles?
These issues are again front and center as immigration enforcement takes on renewed prominence under the second Trump administration. As this legal and political conflict continues, the struggle between federal authority and state autonomy will remain a defining feature of immigration enforcement practices—and a broader battleground for the future of American federalism.
– Bertina Kudrin, Megan Thomas, Niharika Vattikonda, Published courtesy of Lawfare.
