From [HERE] Mayor Rahm Emanuel [official website] and the City of Chicago sued [press release] the Trump administration Monday to stop the implementation of policies that would withhold federal funds from so-called "sanctuary cities." The complaint [complaint, PDF] claims that the the new policies would require Chicago to choose between individuals' constitutional rights and funding for law enforcement. According to the complaint, the policies would enact two new requirements for Chicago and other sanctuary cities in order to receive funding, 

(1) to detain its own residents and others at federal immigration officials' request, in order to give the federal government a 48-hour notice window prior to an arrestee's release; and (2) to give federal immigration officials unlimited access to local police stations and law enforcement facilities in order to interrogate any suspected noncitizen held there, effectively federalizing all of the City’s detention facilities.

The existence and functioning of sanctuary cities have come under fire since the first week of President Donald Trump's administration. From the beginning of the year, some states and cities have proposed legislation to crackdown on sanctuary policies while some cities continue to stand behind their policies [JURIST op-ed]. In June, the California State Assembly passed two bills which, if passed by the senate, will strengthen protections for undocumented immigrant students in public schools from kindergarten through college by preventing Immigration and Customs Enforcement officers from entering a school site without a valid judicial warrant [JURIST report] and approval from the superintendent. In May Texas Governor Greg Abbott signed into law a bill banning sanctuary cities [JURIST report] in the state. In March the Mississippi Senate approved a bill [JURIST report] to prohibit local sanctuary immigration policies. In February the Alabama House approved [JURIST report] a bill to block funding for sanctuary universities. In the same month, Texas Senate approved a bill targeting sanctuary cities [JURIST report] by requiring them to comply with federal immigration law. Earlier in February San Francisco similarly filed a lawsuit against the Trump administration over an executive order that would cut federal funding [JURIST report] from sanctuary cities, including San Francisco.