Chicago has long been a "sanctuary city"—with more robust protections for undocumented immigrants than many other jurisdictions across the nation.

Even so, holes in Chicago’s Welcoming City ordinance have stoked fears in the face of the federal government's anti-immigrant crackdown.

As it stands, the city law limits interactions police and other city employees have with Immigration and Customs Enforcement, a federal agency. Local officials may not ask for a person's immigration status or turn undocumented immigrants over to federal agents. Last fall, City Council amended the ordinance to provide additional protections, barring city officials from threatening to reveal the immigration status of a person to federal officials or verbally abusing immigrants based on their race, citizenship, or country of origin.

But the law still has limitations. Chicago police may communicate with federal agents about undocumented immigrants who have an outstanding criminal warrant, a prior felony conviction, a pending felony prosecution, or are in the city’s gang database. Since Donald Trump's inauguration, immigrant-rights groups in Chicago have stepped up their efforts to end these "carve-outs," culminating in a proposed amendment to the ordinance, sponsored by 28 aldermen, introduced in February—earlier this month, the American Civil Liberties Union joined them.

On the other hand, the Trump administration often cites Chicago as an example of immigrant protections gone too far—recently ICE head Thomas Homan, in a Fox News interview, referred to Chicago when he described sanctuary jurisdictions as "un-American."

So, how does Chicago stack up against other sanctuary-city laws?

You don’t have to look too far to find a place with more extensive protections. In February, the village of Oak Park unanimously passed an ordinance prohibiting city officials, including police, from identifying, apprehending, or transferring undocumented immigrants in Oak Park to federal agents without a valid and properly issued court-ordered criminal warrant.

The ordinance also states that no village agency or agent “shall expend any time, facilities, equipment, information, or other resources of the agency … to facilitate the creation, publication, or maintenance of any federal program to register individuals present in the United States based on their ancestry, national origin or religion.”

Immigrant-rights advocates have lauded Oak Park’s no-exemptions ordinance, calling it one of the most progressive in the nation. According to Fred Tsao, senior policy counsel at the Illinois Coalition for Immigrant and Refugee Rights, the “Oak Park ordinance has provided a template for several other communities including Berwyn, Summit, and Forest Park."

While no major cities have adopted an exemption-free policy like Oak Park's, some have fewer carve-outs than Chicago. Philadelphia refrains from helping federal agents and will only assist with an immigration detainer if it comes with a judicial warrant, Tsao says. San Francisco’s ordinance only exempts individuals in custody for a violent crime or convicted of violent felonies within the past seven years.

Tsao says people have a misconception that ICE doesn’t operate in sanctuary jurisdictions: “ICE operates in the city of Chicago, and other cities that have [sanctuary] policies in place, and they will continue to do that, local ordinance withstanding. Local jurisdictions cannot control what ICE does, for better or worse.”