Chicago Mayor Brandon Johnson voiced concerns Monday about potential federal troop deployment to his city as part of former President Donald Trumps immigration crackdown, warning the move could be unconstitutional and legally challenged.Speaking at a City Hall news conference, Johnson responded to reports of federal plans to escalate immigration enforcement in sanctuary cities like Chicago, calling the idea a threat to civil liberties and local governance."Its just another example of his animus towards working people," Johnson said. "I think its important that the president respects the Constitution. If youre asking me whether this president will work with city leaders, its clear hes not interested in doing that."CHICAGO SUSPENDS ONLINE APPLICATION WEBSITE THAT ALLOWED ILLEGAL IMMIGRANTS TO OBTAIN IDS AFTER ICE SUBPOENAJohnsons remarks came in response to a statement from a Trump administration official to Rolling Stone, saying, "Chicago is next, if they go too far," in reference to recent protests and the citys sanctuary policies."The second they do, the president is prepared to prove that nobody is above the law," the official added.The comments follow anti-ICE and anti-Trump protests in Chicago that echoed demonstrations nationwide, prompting federal officials to reportedly monitor the situation closelyespecially after the Trump administration deployed National Guard forces to Los Angeles."We will continue to resist," Johnson said. "Whether its in the courts, in the streets, or through public policy, were going to stand up for working people."Mary Richardson-Lowry, the citys Corporation Counsel, emphasized the legal limitations of such a deployment. "We believe it is a violation of the Constitution to deploy troops or National Guard absent authority under the Constitution," she said.ILLINOIS PROJECTED TO SPEND $2.5B ON MIGRANTS BY END OF 2025, REPORT CLAIMSLast week, Johnson called for Chicagoans to "rise up" against ICE and what he called immigration enforcement "terrorism."Chicago has received more than 51,000 migrants from the southern border since August 2022, many bussed from Texas under GOP Gov. Greg Abbotts relocation effort.The latest tensions come after Illinois Democratic Gov. J.B. Pritzker testified before Congress last week in defense of the states sanctuary city policies.The mayor's office did not immediately respond to Fox News Digitals request for comment.