CHICAGO (WLS) — An important ruling is expected soon regarding a lawsuit about immigration enforcement in Illinois, which could have significant constitutional consequences.

A judge from the U.S. district court is poised to determine if a federal lawsuit against Illinois, including Cook County and the city of Chicago, concerning the collaboration with immigration enforcement, will proceed or be thrown out.

The ABC7 I-Team reviewed court filings in the case to learn more about the arguments that the U.S. Department of Justice is making.

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The lawsuit was filed in February shortly after U.S. Attorney General Pam Bondi took office.

The federal government contends that Illinois laws restricting cooperation between Immigration and Customs Enforcement (ICE) and local police are unlawfully obstructing immigration enforcement, potentially endangering public safety.

In one example included in the filing, federal officials allege a suspect wanted on an immigration detainer was being held in Cook County jail in August 2024, and following state and local laws, jail officials refused to honor ICE’s detainer.

That individual was released, and months later, the DOJ claims they were “subsequently arrested.. for criminal sexual assault and abuse of a minor.”

The examples listed in the court filings do not include any specific details, such as the suspects names or local law enforcement agencies involved in the investigations.

ABC7 Chief Legal Analyst Gil Soffer said while the Illinois TRUST Act and Chicago Welcoming City ordinance may not be found to be outright illegal, it comes down to how they are enforced.

“The state generally would have a right not to cooperate, or affirmatively volunteer to cooperate with the feds,” Soffer said. “It doesn’t have the right to obstruct the feds, and that’s really the key question.”

Soffer said the case boils down to the line between state and federal rights.

“What are the powers of the feds? What are the powers of the states? How do you separate them, and how do you honor each of them?” Soffer said. “This case calls that very concept into question.”

In their filed arguments, U.S. attorneys assert federal powers are “broad and undoubted over the subject of immigration and the status of aliens,” and that prohibiting collaboration makes immigration enforcement “nearly impossible.”

But immigration enforcement has been occurring in Illinois since President Donald Trump took office for his second term.

While ICE has not released the number of arrests at the local or state level, federal data published by Syracuse University’s TRAC, and reviewed by the I-Team, shows from January to March of this year, 6,430 new deportation proceedings were filed in Illinois immigration court.

Illinois Attorney General Kwame Raoul told the I-Team he believes a judge weighing in on this issue is necessary, even if the issue at the center of the case has been argued and settled before.

“I’m pleased that the Department of Justice chose to sue Illinois first, so that we can get clarity for our local law enforcement departments throughout the state,” Raoul said, adding that this has been litigated twice before.

Raoul said of the verdicts in those cases, “The 10th Amendment protects states against being commandeered by the federal government to do what is the federal government’s work.”

In court filings, the state of Illinois has argued there are no federal laws that compel state or local police to “facilitate or effectuate civil immigration detentions” while underscoring local law enforcement will always comply with federal warrants, separate from detainers.

“Congress’s power to determine who may lawfully be in the United States does not include the power to conscript state and local police as federal immigration agents,” the state has argued.

Raoul said he expects the case to be dismissed.

“There is no state department of immigration enforcement. There is no city department of immigration enforcement,” Raoul told the I-Team. “We’ve accepted for a long time now that that is the job of the federal government.”

Cook County and the city of Chicago have also argued the U.S. has failed to state a claim and the case should be dismissed.

Northern District of Illinois Judge Lindsay Jenkins is expected to make a decision on whether the case moves forward or is dismissed any day now.