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Expert Brief

Federalism as a Check on Abuses by Federal Law Enforcement

States and cities have the power to decide whether and how their police departments collaborate with federal law enforcement.

Published: September 17, 2025

What can state and local law enforcement officials do to protect their communities when federal law enforcement agencies run amok? Unfortunately, this question isn’t hypothetical.

Roving groups of masked federal agents have been jumping out of unmarked vehicles and aggressively arresting anyone who fits the profile of a Latino immigrant. Some were later determined to be U.S. citizens. When community members have gathered to protest these unlawful activities, federal agents have used excessive force to suppress them, backed up by U.S. Marines and National Guard troops called to federal service without the state governor’s approval.

The situation is getting worse. Federal agents kitted up for urban combat are raiding farms and prowling courthouses, schools, and Home Depot parking lots across the country, terrorizing vulnerable communities. President Trump federalized the Washington, DC, police department and deployed National Guard units from several other states to police the city’s streets. Leaked documents reveal that the Department of Homeland Security is seeking military support for immigration raids in Illinois.

The question of what local leaders can do was raised in a June Los Angeles City Council meeting on the forceful and indiscriminate state and local police response to protests against the immigration raids. A city councilor asked how the Los Angeles Police Department (LAPD) might curb the Trump administration’s immigration enforcement abuses. LAPD Chief Jim McDonnell stated that obstructing federal law enforcement was illegal. When questioned about whether his officers’ violent response to the protests were improperly assisting the federal immigration raids, in violation of local sanctuary city laws, McDonnell said the LAPD was obligated to respond to calls for assistance from its federal law enforcement “partners.”

While it’s true that state and local police cannot obstruct legitimate federal law enforcement activities, these joint law enforcement partnerships are not a barrier to state and local control over federal law enforcement policies or practices. To the contrary, these partnerships provide a key mechanism for state and local authorities to check federal abuse by exercising their power to set the conditions for their cooperation, and terminating the partnerships if refused. Because the truth is that federal law enforcement agencies are far more dependent on their state and local law enforcement partners than vice-versa.

The Federalization of State and Local Police

The Constitution established a federal government of limited powers. The 10th Amendment explicitly left powers not delegated to the federal government, nor prohibited by the Constitution, to the states and the people. This federal system divided governmental power between two competing sovereigns so that each could keep the other in check. Policing power — that is, the power to enact laws to promote public safety and the general welfare — is reserved to the states, except where expressly delegated to the federal government, and limited by both state law and the Constitution.

In Federalist No. 45, James Madison argued that states would have a clear advantage over the federal government in the competition between sovereigns. He based this assumption on the limited powers given to the federal government, the states’ stronger connections to local populations, and their collective interest in resisting federal encroachment on state rights.

As the size and power of the federal government grew, through the Civil War, the New Deal, and the civil rights era, the competitive federalism envisioned by the framers transitioned into a new paradigm in which the federal government induced states to support federal initiatives by providing financial grants, imposing mandates, and expanding federal criminal laws. Over time, state and local law enforcement has become entwined with federal law enforcement in ways that can usurp the power of cities and states and challenge their control over their own police officers.

Expansion of federal law enforcement

President Richard Nixon’s war on drugs in the 1970s provided a platform for the expansion of federal law enforcement and the co-optation of state and local law enforcement. Federal officials sought the cooperation of state and local law enforcement, which could contribute significantly more sworn officers to the effort, as well as provide greater knowledge of local communities and crime networks. They established joint law enforcement narcotics task forces, which deputized state and local police officers as federal officers. This allowed the deputized officers to work outside their normal jurisdictional limits and provided them with greater funding, security clearances, and access to federal training, equipment, and classified intelligence systems.

Despite the lack of success in curbing drug trafficking, the federal task force model expanded in the 1980s and 1990s to serve other federal initiatives, including the organized crime and drug enforcement task forces; violent crimes, gangs, and safe streets task forces; the U.S. Marshals’ fugitive task forces; FBI joint terrorism task forces; and border enforcement security task forces. Task forces have proliferated because they are an easy way for the federal government to grow its law enforcement workforce, develop unified strategies, streamline operations, and expand its reach into participating localities. State and local police agencies benefit from these task force arrangements with additional resources, enhanced training opportunities, and access to federal equipment and intelligence systems. But these benefits often come at the cost of public accountability. A 2014 Congressional Research Service report evaluating federal task forces and fusion centers on the southwest border found that “there is no official roster, or task force census, of federally led task forces operating around the country or even in a particular region, nor is there an inventory of those task forces targeting specific threats.” That lack of transparency remains today.

Most controversially, the federal government has encouraged state and local police to assist in immigration enforcement efforts, which is a purely federal function. Through a voluntary program under Section 287(g) of the Immigration and Nationality Act, the Department of Homeland Security can deputize state and local law enforcement officers in participating jurisdictions and authorize them to enforce federal immigration laws. Where state and local agencies have chosen not to enter these formal agreements, police officers have found other means to routinely share immigration-related information with Immigration and Customs Enforcement (ICE), at times in direct violation of state laws and local ordinances.

A multitude of other collaboration mechanisms facilitate information sharing and cooperation between federal, state, and local law enforcement. The most expansive is the national network of state and regional intelligence fusion centers, which were created after the 9/11 terrorist attacks. Originally conceived as a system to share counterterrorism information, fusion centers have expanded their missions to include all crimes, threats, and hazards. They include representatives from state and local law enforcement, emergency response and public health agencies, the National Guard, the FBI, DHS, and select private entities.

Despite the continuing support it provides to fusion centers, the federal government denies ownership or control of these entities and does not regulate the network it established, as the Brennan Center has documented. State and local legislators often have little insight into fusion center activities, however, and don’t have the access, staff, or expertise necessary to conduct effective oversight of their operations, leaving these centers, and the broader network, largely unregulated. Not surprisingly, fusion center abuses targeting an array of minority communities and political dissidents across the political spectrum have proliferated over the decades, unabated. The presence of DHS officials in the fusion centers and the agency’s access to the information that fusion centers collect and share on a regular basis raise concerns that the national network creates a workaround for law enforcement officials to share information with ICE, in violation of sanctuary laws and policies.

Concerns about state–federal law enforcement partnerships

There are undoubtedly benefits that state and local governments can receive through effective collaboration and the timely sharing of relevant criminal intelligence information between federal, state, and local law enforcement agencies. Obviously, no one wants a violent criminal to escape detection and arrest because one law enforcement agency did not share lawfully obtained intelligence information with another agency. But the existing collaborative arrangements between federal, state, and local law enforcement remain opaque, and they have too often led to abuse.

Nor is there much evidence to show they are effective. The 2014 CRS examination of federal task forces and fusion centers determined that, “at the federal level, no uniform metrics exist for either the evaluation of task forces or of the federal strategies that may employ them.” A 2012 congressional investigation found that “fusion centers forwarded ‘intelligence’ of uneven quality — oftentimes shoddy, rarely timely, sometimes endangering citizens’ civil liberties and Privacy Act protections, occasionally taken from already-published public sources, and more often than not unrelated to terrorism.”

Meanwhile, the increased federalization of state and local law enforcement has eroded the ability of state and local officials to maintain democratic controls over their police officers. By joining a federal task force and becoming a deputized federal agent, state and local police officers can skirt state and local laws that limit law enforcement activities more strictly than federal laws and policies. The secrecy with which these federal partnerships operate often prevents state and local officials from even knowing what their officers are doing when assigned to these task forces, hindering proper supervision.

Reclaiming State Power as a Check on Federal Abuse

When federal law enforcement operates in ways that violate state laws, local ordinances, or community values, state and local law enforcement are still obligated to uphold these laws and protect the community from federal abuse. State and local governments can reassert their authority over their police agencies and influence federal law enforcement policy and practices by setting the conditions under which their law enforcement agencies will participate in these partnerships. They can also end partnerships if the federal government refuses to cooperate on their terms.

In 2004, the FBI denied the mayor of Portland, Oregon, who also serves as police commissioner, the security clearances that would allow him to supervise the activities of Portland police officers assigned to a joint terrorism task force. In response, the Portland City Council voted in 2005 to remove the Portland police officers assigned to the task force. Ten years later, Portland returned its officers to the task force, based on a promise of greater transparency and assurances that Portland officers would comply with Oregon law, which more strictly limited the collection of intelligence than federal guidelines. In 2018, the Portland City Council again voted to remove officers from the task force after it improperly targeted Muslim communities and failed to follow through on promises to operate with more transparency.

In 2012, the San Francisco City Council passed an ordinance requiring the San Francisco Police Department to submit annual public reports about its work with the FBI. The joint terrorism task force resisted efforts to comply fully with this requirement, and in 2017 the SFPD suspended its participation in the task force. The Oakland City Council then unanimously passed an ordinance requiring that Oakland Police Department officers assigned to the task force follow state and local law and submit annual public reports. After finding the task force’s reports to be insufficient, the Oakland City Council terminated its police department’s relationship with the task force in 2020.

The aftermath of a police shooting in Atlanta provided an example of how state and local police refusals to participate in federal task forces can drive changes in federal policy. An Atlanta police officer assigned to an FBI fugitive task force wasn’t wearing a body camera — in violation of local policies — when he shot an unarmed fugitive in 2019. Federal policy at the time did not allow task force officers to wear body cameras. Atlanta officials asked for Atlanta police officers assigned to the task force to be permitted to wear the cameras, but the federal government refused. Atlanta then removed its approximately 25 officers from all federal task forces. Several law enforcement agencies in Minnesota also removed their officers from the U.S. Marshals’ fugitive task force in response to the body camera policy, and others around the country publicly contemplated doing the same. Within a year, the Justice Department changed its policies, allowing task force officers to wear body cameras while conducting arrests and executing search warrants, if required by their department policies.

As state entities, fusion centers provide another avenue for state authorities to temper inappropriate federal ambitions, yet few state governments have taken the actions necessary to protect their residents from unlawful surveillance. After a state trooper’s whistleblower report and a massive data leak by a fusion center contractor exposed widespread abuse at the Maine fusion center, the Maine House of Representatives passed a bill in 2021 that would have defunded it. That bill failed in the state senate, but the following year, both houses of the legislature passed a bill that created a state auditor to oversee the fusion center’s operations and issue public reports. It was not funded, however, and did not become law. Still, these bills provide models for future state efforts to reclaim their authorities to properly oversee and regulate the activities of state and local law enforcement.

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The Supremacy Clause of the Constitution makes clear that states cannot nullify federal law or obstruct duly authorized federal law enforcement operations. This safeguard has historically proven useful: During the civil rights era, the federal government correctly interceded to prevent states from depriving Black Americans of the civil and political rights guaranteed in the Constitution. But that doesn’t mean states are powerless to act when the federal government deprives their residents of these same rights and privileges or when its agents violate state laws.

A partnership implies a mutual commitment to cooperate in service of shared goals. If the federal government refuses to cooperate in a manner that state residents, through their elected representatives, demand, states have the right to curtail their participation. State and local law enforcement officials’ primary obligation is not to support their federal partners. Their duty is to enforce state law and defend the communities they swore to protect.