Lawsuits Targeting Sanctuary Policies Test Balance of Federal, State Power

States with such policies said the administration can’t commandeer their resources.

Immigration and Customs Enforcement agents detain a man after a hearing at the Connecticut Supreme Court in Stamford on July 3, 2025. John Moore/Getty Images

President Donald Trump’s administration has sued multiple states and localities for allegedly violating the Constitution by hindering federal immigration enforcement.

These areas, known as sanctuary jurisdictions, have policies or practices that prohibit cooperation with federal authorities in enforcing immigration laws. Trump ordered the federal government to prepare to withhold federal funds from these places, but hit a block after multiple jurisdictions filed lawsuits.

According to the Trump administration, the policies violate federal law and the supremacy clause of the Constitution, which essentially says that states and localities must abide by federal law. States counter that the federal government can’t commandeer or force them to use their resources.

The ensuing constitutional battle could force the Supreme Court to set precedent not only on aspects of the Constitution, but also on the balance of power between states and federal authorities.

Sanctuary Policies

Facing lawsuits from the Trump administration over their sanctuary laws are New Jersey, New York, Colorado, Illinois, and California—along with several of their cities.

The policies in those states, using similar language, forbid law enforcement officers from detaining illegal immigrants for pickup by Immigration and Customs Enforcement (ICE) agents unless required by a criminal arrest warrant. They also forbid local police from assisting or cooperating with ICE, or communicating private information about the immigration status of potential illegal immigrants.

For example, Newark, New Jersey, Mayor Ras J. Baraka’s 2017 executive order stated that the city and its agents “shall not expend any time, funds, or resources on facilitating the civil enforcement of federal immigration law nor participating in civil immigration enforcement operations” unless compelled by law, guidelines from the attorney general, or a court order.

The mayor’s order also stated that police cannot question suspects about their immigration status nor hold them in custody beyond their normal release date at the request of ICE. Officers may not notify ICE when suspected illegal immigrants are to be released from custody.

Policies in Hoboken, Paterson, and Jersey City, New Jersey, are similar.

In 2019, New York state passed its Green Light Law, which allows illegal immigrants to obtain a driver’s license and forbids the Department of Motor Vehicles from sharing information with immigration enforcement agencies.

Colorado is suing a Mesa County sheriff’s deputy who shared information with ICE agents that led to the detention of a young woman whom he’d pulled over during a traffic stop.

Colorado Attorney General Phil Weiser said the deputy violated the state’s laws and was acting outside his authority, especially because the woman was issued a warning and not charged with a crime.

Malik D. Evans, mayor of Rochester, New York, criticized local officers after they responded to a backup request by Border Patrol agents in March.

Government’s Response

The Trump administration said these policies violate federal immigration law.

It points to 8 U.S. Code, Section 1373, which states that state and local governments cannot “prohibit, or in any way restrict, any government entity or official from sending to, or receiving from, the Immigration and Naturalization Service information regarding the citizenship or immigration status, lawful or unlawful, of any individual.”

Other portions of that law mandate that illegal immigrants are to be detained by immigration authorities immediately upon release from state custody and deported within 90 days. That law says that either a civil arrest warrant or a criminal arrest warrant is sufficient for detainment.

“Congress granted this permission expecting that states and local governments would then facilitate, or at the very least not obstruct, detention of criminal aliens by federal immigration authorities,” the federal government argued in its suit against Newark.

What Is Preemption?

Does federal law always trump state law, and if so, how? A legal doctrine known as preemption governs how laws from Congress take precedence over state laws.

This can happen in different ways, but the federal government is essentially arguing that states are interfering with immigration enforcement by not respecting federal law.

In one of Trump’s executive orders, he suggested that the states’ immigration-related policies constitute a form of insurrection. “This is a lawless insurrection against the supremacy of Federal law and the Federal Government’s obligation to defend the territorial sovereignty of the United States,” he said in April.

The sanctuary states and localities have attempted to defend themselves by arguing that their laws don’t conflict with federal law.

In Illinois, a federal judge seemed to agree when dismissing the Trump administration’s lawsuit against the state and two local governments, including Chicago, saying that the sanctuary policies don’t obstruct ICE’s operations.

“There’s no doubt—particularly at the motion-to-dismiss stage where well-pleaded allegations are presumed true—that, absent the Policies, it might be easier for immigration agents to discharge their obligations under the [Immigration and Nationality Act],” U.S. District Judge Lindsay Jenkins said.

“But because the [Immigration and Nationality Act] merely offers States the opportunity to assist in civil immigration enforcement, the Policies don’t make [Immigration and Customs Enforcement’s] job more difficult; they just don’t make it easier.”

10th Amendment

Part of Jenkins’s opinion acknowledged that certain aspects of Chicago and Illinois law seemed to conflict with federal law. She added, however, that the jurisdictions were still protected by the 10th Amendment of the Constitution, which shields them from taking orders from the federal government.

The amendment says that the powers not granted to the federal government are reserved for the states. Courts have interpreted this amendment to mean that the federal government can’t “commandeer” or force states to use their resources for federal purposes.

The prohibition on commandeering state resources has popped up in many of the sanctuary lawsuits and was cited by a California judge, who blocked the administration’s attempt to defund these jurisdictions.

The Justice Department has made various arguments in response, including that it is merely trying to remove barriers that hinder federal immigration enforcement rather than force state involvement. It has also said that the jurisdictions are discriminating against the federal government by working with other law enforcement agencies but not federal immigration enforcement.

It’s unclear how other judges will rule, but Jenkins rejected that argument in her July opinion. She said the administration had failed to show how another agency “similarly situated” to Immigration and Customs Enforcement was receiving better treatment.