Back in September, while giving his highly anticipated speech on immigration in Phoenix, Arizona, then-Republican presidential nominee Donald Trump promised to block federal funding for so-called sanctuary cities—a term for those that have vowed not to criminalize undocumented immigrants based on citizenship status alone.

“Block funding for sanctuary cities … no more funds,” Trump said in Phoenix. “Cities that refuse to cooperate with federal authorities will not receive taxpayer dollars, and we will work with Congress to pass legislation to protect those jurisdictions that do assist federal authorities.”

As CNN reported, broadly speaking, a sanctuary city has “policies or laws that limit how much local law enforcement and government agencies can work with federal authorities on immigration matters.” Last year, Immigration and Customs Enforcement (ICE) Director Sarah Saldaña told Congress that more than 200 state and local jurisdictions have policies that call for not honoring ICE detention requests. According to Politico, these jurisdictions believe such requests “are unconstitutional and foster mistrust between immigrant communities and police.”

Since the election, mayors from across the country have stepped forward to reassure undocumented immigrants that they are safe in their cities. An existing ICE program, however, means that may not necessarily be the case.

Priority Enforcement Program Complicates Sanctuary Cities

An ICE policy known as the Priority Enforcement Program (PEP) severely complicates the narrative of sanctuary cities. PEP is basically a continuation of the now-defunct, highly controversial Secure Communities (S-Comm) program put into place by President George W. Bush and escalated under President Obama, whose administration oversaw record numbers of deportations as a direct result of the program.

As Rewire has reported, S-Comm required local law enforcement agencies to submit biometric information from anyone they arrested into a federal database. According to the American Civil Liberties Union (ACLU), this meant that “any time an individual was arrested and booked into a local jail for any reason, [their] fingerprints [were] electronically run through ICE’s immigration database. This allows ICE to identify people who may be non-citizens—including lawful immigrants and permanent residents—and potentially to initiate deportation proceedings against them.”

“Because it [targeted] people at the time of arrest, not conviction, S-Comm [captured] people who will never be charged with a state crime—including crime victims (including domestic violence victims), witnesses, and individuals who were wrongly arrested,” the ACLU reported. ICE would then submit a “detainer”—a written request—requiring local law enforcement to hold the undocumented person until they could get picked up for deportation. The program ended in 2014 and was swiftly replaced by PEP.

Under PEP, fingerprints obtained by local law enforcement are still sent to ICE, so any interaction an undocumented person has with them can still potentially lead to their deportation. The only real difference between S-Comm and PEP, as Frontline reported in November 2014, is that ICE should now “only issue detainers for those in the country illegally who have been convicted of serious offenses or those who pose a risk to national security.” The problem with this is two-fold: a “serious offense” can encompass many things—especially for immigrants, whose undocumented status often causes them to suffer trumped-up charges and consequences. Secondly, as Frontline reported, officials can still issue a detainer “if they believe they have probable cause to deport someone who hasn’t yet been convicted” of the crime for which they were charged, which can result in people who are lower priorities being deported.

Local law enforcement agencies can choose whether or not they want to participate in PEP. In August 2015, the Washington Post reported that according to the Department of Homeland Security (DHS), “more than 30 of the nation’s largest law enforcement agencies have indicated a willingness to work with the agency on PEP.” Even if a city calls itself a sanctuary city, biometrics of those arrested are still generally available to ICE, and agencies in the immediate area may still participate in PEP. For example, the city of Los Angeles does not participate in PEP, but Los Angeles County does.

“The Devil is in the Details”

Alexis Teodoro, an organizer with the National Day Laborer Organizing Network, told Rewire that over the years, the idea of “sanctuary” has become somewhat symbolic, as many jurisdictions offer little more than statements of solidarity, rather than “law-binding policies that have accountability measures.”

Teodoro cited the Los Angeles Police Department (LAPD) as a perfect example of this. Many were happy to hear the LAPD’s recent announcement that it will not cooperate with ICE. But for years, the LAPD has collaborated with ICE on “joint” enforcement and removal operations. Teodoro strongly believes this will continue through the Homeland Security Investigations (HSI)’s National Gang Unit, which forges partnerships with local law enforcement and creates a direct link between the criminal justice system and the detention system.

“The devil is in the details. City sanctuary resolutions are just simple statements. What cities need is a local, law-binding [resolution] with accountability measures in place.” Such measures, he said, should hold police responsible if they go against “sanctuary city” policies and help to shield city agencies hoping to better protect vulnerable, undocumented community members.

Not all states have the same policies for sanctuary cities, and there is no unifying definition or law in the more than 200 jurisdictions that identify themselves as such. The Atlantic‘s CityLab recently compiled a list of major cities with policies on the books vowing to protect undocumented immigrants. Some, like Chicago’s, go back 30 years; other cities, like Philadelphia, seem to be moving away from the the phrase “sanctuary city,” minimizing the focus on undocumented immigrants while maintaining the policy.

Sanctuary City Protections Largely Defined by Local Law Enforcement

Undocumented organizer Claudia Muñoz, who has lived in several places across the country that purport to be “sanctuary cities,” told Rewire that approaches vary drastically depending on where you live. In some cities in the South, for example, it has been her experience that an undocumented person who gets pulled over for driving without a license could get sent to jail and then placed in deportation proceedings, Muñoz said. In New York City, however, the same situation could result in a mere warning or a traffic ticket, according to the organizer.

Muñoz claims that New York City is the “most proactive” about making undocumented people feel safe, which is why she has family members in Texas who are considering a move to the city, depending on how things play out with the Trump administration. Nonetheless, she said she also knows that nowhere is safe for undocumented immigrants who have even the most minor of charges, like possession of marijuana. This is a direct result of what are known as the 1996 laws, which allowed the government to redefine “what it means to be a ‘criminal alien,’ using increasingly stringent definitions and standards of ‘criminality’ that do not apply to U.S. citizens,” according to the American Immigration Council.

For the organizer, one of the biggest issues with sanctuary cities is that undocumented immigrants are never consulted in how they are defined or what they entail.

“I feel like if officials were serious about sanctuary cities, they would ask us undocumented immigrants what that means because right now it’s largely defined by [officials]. I think this is important to point out, especially under a Trump presidency,” Muñoz said.

Like Teodoro, Muñoz also wants to see concrete, law-binding policies in place that protect undocumented immigrants in sanctuary cities, but she is unsure how effective they would be given ICE’s continued role in the criminal justice system.

Even in New York City, which has the some of the most thorough policies in place to protect undocumented immigrants, there are loopholes that have ICE working with local law enforcement and that force the New York Police Department (NYPD) to abide by detainers. Generally speaking, the NYPD no longer honors ICE detainer requests, but the Immigrant Defense Project (IDP) reports that the NYPD will hold those with detainers for up to 48 hours under special circumstances. The NYPD will give ICE 48 hours to secure a judicial warrant, according to IDP, in two situations: if an undocumented immigrant has been convicted of a “violent or serious crime” at any time in the past and has reentered the United States after being deported, or if the person is a possible match on the terror list.

“[New York City Mayor Bill] de Blasio can go on record and say as much as he wants about sanctuary and that’s a good start, but that won’t actually protect many people,” Muñoz said. “If they don’t allocate resources or have policies in place that limit collaboration with ICE, ICE can still show up at anyone’s door and detain them if they fall within their priorities.”

Safer(er) Spaces: A List of Sanctuary Cities

As January approaches and we move closer to entering the age of the Trump administration, it still remains unknown how many of Trump’s anti-immigrant promises will come to fruition. Here’s what we do know: Cities and states can’t be forced to enforce federal law, but federal agents can move in at any point. Also, “there’s no U.S. requirement that police ask about a person’s immigration status,” NBC reported. This means that any effort made by Trump to crack down on sanctuary cities will likely target those that outright refuse to comply with ICE requests without judges’ orders, such as New York City and Los Angeles.

We also know that Trump plans to detain and deport between two and three million undocumented immigrants immediately upon taking office, according to a CBS interview that aired last week. For context, President Obama, who is routinely called “Deporter-in-Chief” by immigrant rights activists, has deported nearly three million people in his eight years as president.

In anticipation of feared large-scale efforts to target undocumented immigrants, various communities are setting the groundwork to protect vulnerable migrants. On Change.org, there are currently at least 23 petitions circulating to protect sanctuary cities. Students from across the country are calling on their colleges to “limit their cooperation with federal immigration enforcement authorities and to declare theirs ‘sanctuary campuses,’” Insider Higher Ed reported. The Mexican government has even released an 11-step plan to protect Mexican citizens currently residing in the United States. And in the days since Trump became president-elect, mayors from across the country have reasserted their commitments to remaining sanctuary cities.

Rewire has compiled a list of cities that have committed to protecting undocumented immigrants (to the best of their ability, presumably) since Trump was elected. Last updated: Tuesday, December 13, 5:03 p.m.

California

In 2013, Gov. Jerry Brown signed a bill known as the Trust Act, preventing jails from honoring federal requests to hold undocumented immigrants after their release date unless they have been convicted of or charged with serious or violent felonies. The law essentially allows the state to protect undocumented immigrants from deportation for low-level crimes. In the years since, court decisions have upheld that legal precedent by allowing jails to discharge undocumented immigrants when they are eligible for release, rather than holding them for ICE. “The Trump administration could sue California over the 2013 law, perhaps arguing the statute is pre-empted by federal law,” according to the Sacramento Bee.

Los Angeles: Mayor Eric Garcetti said California will continue limiting compliance with ICE detainer requests. Police chief Charlie Beck also recently said the LAPD would not aid in the deportation of immigrants under President-elect Trump.

Oakland: In an op-ed for the East Bay Express, Oakland Mayor Libby Schaaf wrote that the city will “proudly stand as a sanctuary city,” protecting residents from “unjust federal immigration laws.” The mayor also committed to helping other regions become sanctuary cities. As for the president-elect’s vow to block federal funding for sanctuary cities, Schaaf wrote, “California and local Bay Area governments can enact our own laws and allocate our own funds, consistent with our progressive values.”

San Francisco: On the campaign trail, Trump regularly cited the murder of Kathryn Steinle, allegedly by an undocumented homeless man in San Francisco, to stoke fears about undocumented immigrants, but the city’s mayor, Ed Lee, recently assured migrants that its commitment to being a sanctuary city remained firmly in place. “Being a sanctuary city is in our DNA,” Lee tweeted. “San Francisco will never be anything other than a sanctuary city.”

San Francisco Supervisor David Campos, who was undocumented when he first came to the United States, also recently proposed that the city spend $5 million a year for the express purpose of hiring ten on-staff attorneys and support staff to help those facing deportation.

Santa Ana: The Santa Ana City Council unanimously voted in early December to declare Santa Ana a sanctuary city at the urging of local activists, who “pressured the council to move beyond a symbolic sanctuary city resolution” and deepen its commitment, the OC Weekly reported. For now, it’s simply a resolution, but the impending council plans to create a task force to develop an actual ordinance for the city.

Colorado

Aurora: Police Chief Nick Metz recently said that Aurora police will not investigate or detain people based on immigration status. “It is our goal to ensure that all individuals within Aurora feel safe in reporting emergencies,” Metz said.

Denver: Denver Mayor Michael Hancock recently said, “We are not going to do the job of the federal government. What we are going to do is make sure we remain an inclusive city.”

However, both Aurora and Denver have “no ordinances that specifically prohibit police officers or other city officials from helping federal authorities enforce immigration law,” according to the Denver Post.

Illinois

Chicago: For three decades, Chicago’s status as a sanctuary city has taken shape in a very specific way: Government workers and police officers are prohibited from inquiring about a person’s immigration status, and local law enforcement doesn’t participate in PEP. Mayor Rahm Emanuel recently assured undocumented immigrants he will continue working to save them from deportation. “You are safe in Chicago, you are secure in Chicago and you are supported in Chicago,” Emanuel said. “Chicago will always be a sanctuary city.”

Aurora: Police Chief Kristen Ziman wrote in a November 18 Facebook post. “A police officer will NOT ask your status on a traffic stop or if we are called to your home. Even in misdemeanor arrest situations, we are NOT going to inquire about immigration status. … The only time we pursue that avenue is in conjunction with the federal agencies when there is a VIOLENT OFFENDER,” Ziman wrote.

Massachusetts

Cambridge: Cambridge Mayor E. Denise Simmons and City Manager Louis A. DePasquale released a joint statement in mid-November explaining that the city has been a sanctuary city since 1985, in support of refugees fleeing violence in El Salvador, Guatemala, and Haiti. “In 1999, the City Council expanded that support to all residents, regardless of immigration status, and has regularly reaffirmed that over the last 20 years. Today, the City of Cambridge remains just as committed to all of our residents as we have been over the past 31 years,” the statement reads.

Minnesota

Minneapolis: Under Minneapolis ordinance, “law enforcement officers are not to ‘take any law enforcement action’ for the sole purpose of finding undocumented immigrants, or ask an individual about his or her immigration status,” according to City Pages. Minneapolis Mayor Betsy Hodges recently said that Trump’s threat to pull federal funding from sanctuary cities is part of his “quest to scapegoat immigrants” and it will have no impact on the city’s current policies.

New Jersey

Newark: Newark, like many other large cities, does not hold undocumented immigrants in jail at the request of ICE unless the detainer is accompanied by a judge’s order. Newark Mayor Ras Baraka recently said, “Despite the election of Donald Trump, we see no reason to change that policy.”

New Mexico

Santa Fe: This city’s sanctuary status means that police don’t question whether people suspected in minor crimes are undocumented, and they don’t turn over undocumented immigrants accused of low-level offenses to ICE. Santa Fe Mayor Javier Gonzales recently said that the city stands by its commitment of human rights for all immigrants. The status as a sanctuary city “has benefited our people, made us a safer, more cooperative community, and strengthened our economy, and we have no intention to reverse course or be bullied into abandoning our values,” the mayor said.

New York

New York City: New York has severely limited its cooperation with immigration authorities seeking to deport undocumented immigrants. Like Los Angeles, New York does not hold undocumented immigrants in jail at the request of ICE “unless the detainer request is accompanied by a judge’s order,” Reuters reported. Shortly after Trump’s election, Mayor Bill de Blasio said at a news conference that New York City is committed to protecting undocumented immigrants and keeping families together.

Oregon

Ashland: In November, Ashland Police Chief Tighe O’Meara shared on Facebook that “the entire State of Oregon is a ‘sanctuary’ state. That is, by law, no state or local resources can be used to investigate or enforce non-criminal immigration matters. So APD officers cannot put any resources into this as a matter of law, nor can any other non-federal officers in the state of Oregon.” At a November city council meeting, Ashland’s Mayor John Stromberg, city attorney Dave Lohman, and O’Meara reaffirmed Ashland’s commitment to being a sanctuary city with “no intention of changing that,” the Ashland Daily Tidings reported.

Portland: Mayor-elect Ted Wheeler told Oregon Public Broadcasting’s All Things Considered that Portland will remain a sanctuary city. “We’re willing to sacrifice those dollars and we are willing to live with whatever consequences may come our way,” Wheeler added. He said he is currently consulting with immigration attorneys to ensure the state’s legal framework is sufficient to protect undocumented immigrants.

Pennsylvania

Philadelphia: Mayor Jim Kenney recently told a local news outlet the city is essentially rebranding, calling itself a “Fourth Amendment city” instead of a “sanctuary city.” Kenny said the city will “live up to the Fourth Amendment, which means you can’t be held against your will without a warrant from the court signed by a judge. So, yeah, we will continue to be a Fourth Amendment city abiding by the Constitution,” he told the Philadelphia Inquirer. Like New York and Los Angeles, Philadelphia will continue blocking police from complying with ICE detainer requests and refusing to notify federal officials when an undocumented person is released from jail, “unless that person has been convicted of a violent felony and federal agents have obtained a warrant,” the Philadelphia Inquirer reported.

Rhode Island

Providence: This city illustrates what an ambiguous designation “sanctuary city” can be. In Providence, police can—and do—hold undocumented immigrants charged with a crime with an immigration detainer. But the city refuses to hold those who have only been charged with minor civil infractions, such as violating a city ordinance, even if an ICE detainer exists for them. Mayor Jorge Elorza recently said he plans to continue this policy. “I’ve been in touch with both mayors [from New York and L.A.] and I’ve told them we’re going to stand together on this,” Elorza told the Providence Journal. “We’re not going to sacrifice any of our people and we’re going to continue with the policy we always had.”

Vermont

Burlington: Burlington Mayor Miro Weinberger said in mid-November he would ask the city council to make Burlington a sanctuary city. Though there has not yet been any formal announcement, the city has since passed a resolution continuing its practice of not inquiring about residents’ federal immigration status during the provision of city services. The resolution also calls for a new committee, in partnership with the mayor, to “create formal city policies consistent with our long-standing practices related to ensuring that Burlington is a welcoming and inclusive city for immigrants.”

Montpelier: The Montpelier City Council voted in early December to become a sanctuary city. While the official resolution is still in the works, it appears Montpelier is providing some solid groundwork for real-deal protections for the undocumented. A proposed resolution says the city “has no formal existing agreements to enforce immigration policy” and “does not inquire about a resident’s immigration status in providing municipal services or in the course of law enforcement.” The city also will not respond to requests from a state or federal agency “that requires the identification of a resident’s immigration status or religious affiliation.”

Winooski: In this tiny Vermont town, police officers do not inquire about a person’s citizenship status. This week, Mayor Seth Leonard put forward a city council resolution to formally make the town a sanctuary city, guaranteeing that “agency members shall not dedicate time or resources to the enforcement of federal civil immigration law where the only violation of law is presence in the United States without authorization or documentation.”

Washington

Seattle: In 2003, Seattle passed an ordinance preventing police from inquiring about a person’s citizenship status, in a policy similar to Chicago’s. Recently, Mayor Ed Murray said Seattle would remain a sanctuary city, “guided by equality and inclusion and openness.”

Washington, D.C.

Almost a week after the election, Mayor Muriel Bowser assured undocumented immigrants that Washington, D.C.’s  status as a sanctuary city “did not change on election day” and that all D.C. residents are to be respected “no matter their immigration status.”

CORRECTION: This piece has been updated to clarify Claudia Muñoz’s experiences with various cities’ law enforcement and immigration policies.