LAWRENCE, Mass. — A Massachusetts city on Wednesday sued to block President Donald Trump’s executive order cutting off federal funding to cities that refuse to cooperate with federal authorities in identifying and holding illegal immigrants, putting it at the forefront of a nationwide battle over Trump’s immigration policies.

The lawsuit filed by Lawrence — a city of 78,000 with an immigrant population of nearly 40 percent — was joined by the nearby city of Chelsea.

The suit calls Trump’s order a “gun to the head” and asks the U.S. District Court in Boston to declare it unconstitutional. Other larger cities, including San Francisco and Boston, are also suing over the order, arguing that it defies the separation of state and federal powers as put forth in the Tenth Amendment.

The suit opened a second front against Trump’s immigration policies, this one targeting approximately 400 so-called sanctuary cities nationwide that limit cooperation with immigration authorities. 

“The executive order seeks, without congressional authorization, to commandeer local officials to enforce the federal government’s immigration policies and threatens municipalities with crippling losses of funding, apparently including funding for programs with no connection to law enforcement, if the municipalities do not come to heel,” Lawrence and Chelsea allege in their suit. “Particularly for smaller and more impoverished cities and towns, the impact of this executive order is both immediate and chilling.”

Life in Lawrence would change dramatically without federal aid. Lawrence is the poorest city in Massachusetts by many measures. Washington sent $37.8 million to the city in the fiscal year that ended June 30, 2016, to support dozens of services and programs administered mostly by the city and the schools. The federal government spent at least $15 million more for other programs run by the Greater Lawrence Community Action Council, including one that provides winter heating subsidies to 10,000 families and another that provides day care for 700 children of the city’s working poor.

European and Canadian immigrants flocked to Lawrence in the mid-19th century to work in the city’s textile mills. Lawrence has continued to be a haven for immigrants and refugees ever since.

Lawrence joined the list of sanctuary cities on Aug. 12, 2015, when the City Council voted 7-2 to direct police to disregard requests from the federal Department of Immigration and Customs Enforcement “seeking information about an individual’s incarceration status,” unless the agency has a warrant signed by a judge. The bill also forbids police from seeking to determine the immigration status of people they arrest for minor violations or crimes, such as a traffic violation or a nonviolent domestic dispute.

On Wednesday, Mayor Daniel Rivera told the North Andover, Massachusetts Eagle-Tribune the lawsuit grew out of a text message he received from Ivan Espinoza-Madrigal, executive director of the Lawyers Committee for Civil Rights and Economic Justice, a Boston nonprofit. The organization earlier helped Lawrence get an exemption from a federal settlement agreement that had the unintended consequence of limiting the number of minority police officers the city could hire. 

The text came a few days after Trump signed the executive order cutting funding from sanctuary cities.

“We should talk,” Rivera said Espinoza-Madrigal told him in his text message. “We think we can help you with this.”

“I said, ‘I think that’s a good idea,’” Rivera said.

Trump’s executive action does not name any specific municipality, but directs the federal departments of Justice and Homeland Security to identify them. Rivera said he believes the departments will rely on a list of sanctuary cities compiled by the Center for Immigration Studies, a nonprofit organization seeking to limit immigration. Lawrence and Chelsea are on the list.

Eddings writes for the North Andover, Massachusetts Eagle-Tribune.