The lawsuit argues that the U.S. Constitution’s Supremacy Clause “prohibits Illinois, Chicago, Cook County, and their officials from obstructing the Federal Government’s ability to enforce laws that Congress has enacted or to take actions entrusted to it by the Constitution.”

The U.S. government sued Illinois and the city of Chicago on Thursday, accusing them of impeding the Trump administration's immigration enforcement policies. Citing a national emergency declared by President Donald Trump on Inauguration Day,

The Trump administration has sued Illinois and Chicago, alleging its laws are impeding on federal efforts to enforce immigration laws.