AMNA NAWAZ: One of the biggest questions as Trump's second term begins is just how wide and how quickly his administration will conduct mass deportations of undocumented immigrants.

As we reported earlier, those operations got under way this weekend in Chicago and other cities around the country.

Stephanie Sy has our report.

STEPHANIE SY: As part of a nationwide enforcement blitz that resulted in nearly 1,000 arrests on Sunday, President Trump's border czar, Tom Homan, was on the ground in Chicago.

In an interview aired yesterday, Homan said the priority was nabbing people with criminal records.

TOM HOMAN, White House Border Czar: If you're in the country illegally, you're on the table, because it's not OK to violate laws of this country.

You got to remember, every time you enter this country illegally, you violated a crime under Title 8, United States Code 1325.

It's a crime.

STEPHANIE SY: Other federal agencies, like the Drug Enforcement Administration and the FBI, were involved in arrests with Immigration Customs Enforcement in states like California, Colorado, Texas, Arizona, and Georgia.

In Chicago, immigrant enclaves were on edge.

On the city's Northwest Side, nonprofit Onward House provides support services for migrants, including this woman.

She says she came to the U.S. from Mexico with her family a year ago to flee gang violence.

WOMAN (through translator): I am terrified if they catch me or my husband, because then my kids will be all alone in this country.

I have given my children phone numbers of people they can call if something were to happen to us.

I am praying to God it doesn't.

STEPHANIE SY: She says she's had trouble finding a lawyer to help her file an asylum application.

Even under Biden, routes to claim asylum status were narrowed.

Trump has moved to suspend asylum completely.

WOMAN (through translator): We can't set foot inside our country.

That's why we ask the U.S. government for help, so they can assist us, so we don't have to go back because the gangs were going to kill my kids, kill me and my husband.

EMILIO ARAUJO, Onward Neighborhood House: I think there's a lot of fear out there right now.

STEPHANIE SY: Emilio Araujo says Onward House has been a key service provider for many of the more than 50,000 migrants that arrived in Chicago since the summer of 2022, many seeking asylum after being bused from the southern border.

But, in recent months, it's been preparing its clients for what to do if they are approached by law enforcement.

EMILIO ARAUJO: Getting out information like know your rights information, connecting with families, make sure that they have a plan in case they are arrested or detained or anything like that, and, really, the safety piece is where we're at right now is, we need to make sure people are safe so that they can continue to live their lives and build from there.

STEPHANIE SY: During the Biden years, safe spaces for undocumented migrants included churches and schools.

The Trump administration says those so-called sensitive areas thwart law enforcement and reversed the policy on Trump's first day in office.

PEDRO MARTINEZ, CEO, Chicago Public Schools: I want families to be assured our schools are safe.

STEPHANIE SY: But administrators from Chicago Public Schools said they won't coordinate with ICE and agents could not enter the school without a criminal warrant.

PEDRO MARTINEZ: There is complete alignment here between our state, our city and our district.

STEPHANIE SY: On Friday, school officials at a South Side elementary school refused to allow agents that they thought were with ICE into the school.

They turned out to be Secret Service officers unrelated to immigration enforcement.

School officials said fear of children being swept up in the dragnet drove the mistaken claim.

Lawrence Benito is with the Illinois Coalition for Immigrant and Refugee Rights.

He says the Illinois TRUST Act and Chicago's welcoming city ordinance currently prevent police from coordinating with ICE on any civil immigration enforcement, but worries so-called sanctuary laws are under threat.

LAWRENCE BENITO, Executive Director, Illinois Coalition for Immigrant and Refugee Rights: We're asking people to make their voices heard, make sure that their elected officials know that this is not the America that they want to see happen, because I just don't see how they get to the scale that they're talking about without tearing families apart, without tearing mixed families apart, where you have maybe undocumented parents and citizen children.

What are we going to do in those situations?

STEPHANIE SY: Recent ICE enforcement actions have already come under fire.

In Newark, New Jersey, federal agents reportedly arrested undocumented people and questioned U.S. citizens, including a veteran last Thursday at a seafood distributor.

Local officials accused the agents of entering the business without a warrant.

RAS BARAKA (D), Mayor of Newark, New Jersey: We have a Constitution of the United States that we want to uphold.

We have this for a very specific reason, to guard us against illegal trespass like this.

STEPHANIE SY: Even before Trump took office, ICE raids under the Biden administration were taking place, including in Newark, where 33 undocumented immigrants were arrested in December.

Back in Illinois, Governor J.B. Pritzker said he supports deporting criminals and said local law enforcement would cooperate with federal officials when there was a signed warrant.

But he's worried about others that might be getting swept up in the process.

GOV.

J.B. PRITZKER (D-IL): They're going after people who are law-abiding, who are holding down jobs, who have families here, who may have been here for a decade or two decades, and they're often our neighbors and our friends.

And why are we going after them?

STEPHANIE SY: Chicago restaurant owner Sam Sanchez says foreign-born workers have been indispensable to his industry and, like Governor Pritzker, he supports a pathway to legal status for longtime residents.

SAM SANCHEZ, Third Coast Hospitality: The need of construction workers, the need for agriculture, farming, hospitality, hotels, I mean, senior care, these are the workers we need.

STEPHANIE SY: Nevertheless, Sanchez, who met last month with Tom Homan, says he supports the administration's approach to deporting migrants, acknowledging there may be collateral damage.

SAM SANCHEZ: We need law and order in this country, law and order in the city to see it prosper.

But, unfortunately, if he has to knock on doors, he will take grandma and grandpa too if they're here undocumented.

And I believe him.

I think what everybody wants is to deport the criminals, secure the border and make us safe.

STEPHANIE SY: But, on the streets of Chicago, safe is the last thing that many residents feel now.

For the "PBS News Hour," I'm Stephanie Sy.