When U.S. President Donald Trump threatened to flood Chicago with national guard troops and Immigration and Customs Enforcement agents earlier this month, Illinois Gov. J.B. Pritzker said the president lacked the legal authority.

But privately, Pritzker and Chicago Mayor Brandon Johnson began discussing what they could do to shield Chicago from a federal deployment like those underway in two other Democrat-run cities with Black mayors — Los Angeles and Washington, D.C.

Their conclusion: not much.