Justice Dept. to Investigate Local Officials Who Obstruct Immigration Enforcement

The Justice Department is threatening to prosecute state and city officials who refuse to help the Trump administration carry out its immigration agenda, a provocative move that will reignite President Trump’s first-term fight with liberals over “sanctuary” policies.

In a three-page memo, dated Tuesday and intended as guidance to all department employees for carrying out Mr. Trump’s executive orders seeking to limit immigration and foreign gangs, interim leaders at the department have told U.S. attorneys around the country to investigate law enforcement officials who decline to enforce the administration’s immigration policies.

The memo asserts that state and local officials are bound to cooperate with the department under the Constitution’s Supremacy Clause and could face criminal prosecution or civil penalties if they fail to comply.

The memo came as the Homeland Security Department prepared to make targeted raids in cities, including Chicago, with high numbers of undocumented immigrants.

The document underscored the central role the Justice Department will play in enforcing Mr. Trump’s hard-line immigration agenda. It sets up the possibility of a pitched fight between states and cities that decline to comply with government directives. The Trump administration has long battled Democrats in sanctuary cities and counties — those that refuse to hand over immigrants detained by the police to federal immigration authorities — and threatened to prosecute them during Mr. Trump’s first term.

“Federal law prohibits state and local actors from resisting, obstructing and otherwise failing to comply with lawful immigration-related commands,” wrote Emil Bove III, the department’s interim deputy attorney general and a former member of the president’s criminal defense team.