As light snow fell outside, worshippers gathered at Lincoln United Methodist Church in Chicago to pray and plan for what will happen when Donald Trump takes office next week, when the president-elect has promised to begin the largest expulsion of undocumented immigrants in US history.

“The 20th [of January] is going to be here before we know it,” Reverend Tanya Lozano-Washington told the congregation, after passing out steaming cups of Mexican hot chocolate and coffee to warm the crowd of about 60.

Located in Pilsen, a mostly Latino neighbourhood, the church has been a long-time hub for pro-immigration activists in the city’s large Hispanic community. But Sunday services are now English-only, since in-person Spanish-language services were cancelled.

The decision to move them online was made over fears that those gatherings might be targeted by anti-immigration activists or Immigration and Customs Enforcement (ICE).

The incoming president has said he will deport millions of illegal immigrants, threatened workplace raids, and reports suggest that he could do away with a longstanding policy that has made churches off-limits for ICE arrests.

According to one parishioner, American-born David Cruseno, “the threat is very real. It’s very alive”.

Cruseno said his mother entered the country illegally from Mexico but has been working and paying taxes in the US for 30 years.

“With the new administration coming in, it’s almost like a persecution,” he told the BBC. “I feel like we’re being singled out and targeted in a fashion that’s unjust, even though we co-operate [with] this country endlessly.”

But across the country, over 1,400 miles (2,253km) to the south in Texas’s Rio Grande Valley, another mostly immigrant community has a very different take on the impending inauguration – a sign of how Latino communities have become starkly divided on illegal immigration and Donald Trump’s approach to the US-Mexico border.

“Immigration is essential… but the right way,” said resident David Porras – a rancher, farmer and botanist.

“But with Trump, we’re going to do it correctly.”

The region is separated from Mexico only by the dark, shallow, narrow waters of the river and patches of dense vegetation and mesquite – locals say that the day-to-day realities of living on the border have increasingly opened their eyes to what many see as the dangers of illegal immigration.

“I’ve had families [of migrants] come knocking on my backdoor, asking for water, for shelter,” said Amanda Garcia, a resident of Starr County, where nearly 97% of residents identify as Latino, making it the most Latino county in the US outside of Puerto Rico.

“We had once incident where a young lady was by herself with two men, and you could tell she was tired – and being abused.”

Over dozens of interviews in two of the Rio Grande Valley’s constituent counties – Starr and neighbouring Hidalgo – residents described a litany of other border-related incidents, ranging from waking up to migrants on their property to witnessing busts of cartel stash houses used for drugs, or dangerous high-speed chases between authorities and smugglers.

Many in the overwhelmingly Latino part of Texas are themselves immigrants, or the children or grandchildren of immigrants. Once a reliable Democratic stronghold in otherwise “Red” Texas, Starr County swung in Trump’s favour in the 2024 election – the first time the county was won by Republicans in over 130 years.

Nationally, Trump garnered about 45% of the Latino vote – a mammoth 14 percentage-point bump compared to the 2020 election.

The victory in Starr County, locals say, was in no small part due to Trump’s stance on the border.

“We live in a country of order and laws,” said Demesio Guerrero, a naturalized US citizen originally from Mexico who lives in the town of Hidalgo, across the international bridge from the cartel-plagued Mexican city of Reynosa.

“We have to be able [to say] who comes in and out,” added Mr Guerrero, speaking in Spanish just metres from a brown, tall metal barrier that represents the end of the US. “Otherwise, this country is lost.”

Like other Trump supporters in the Rio Grande Valley, Mr Guerrero said – repeatedly – that he “is not against immigration”.

“But they should do it the right way,” he said. “Like others have.”

Trump “is not anti-immigrant, or racist at all,” agreed Marisa Garcia, a resident of Rio Grande City in Starr County.

“We’re just tired of them [undocumented immigrants] coming and thinking they can do whatever they want on our property or land, and taking advantage of the system,” she added. “It’s not racist to say that things need to change, and we need to benefit from it also.”

Support for deportations is so strong that the Texas State Government offered Donald Trump 1,400-acres (567 hectares) of land just outside Rio Grande City to build detention facilities for undocumented migrants – a controversial move the American Civil Liberties Union (ACLU) of Texas described as “mass caging” that will “fuel civil rights violations”.

While the patch of land – nestled between a peaceful farm-to-market road and the Rio Grande – is currently quiet, officials in town believe it could ultimately be a boon for the area.

“If you look at it from a developmental way, it’s great for the economics of the city,” Rio Grande City manager Gilberto Millan told the BBC.

“It’s got some negative connotations to it, obviously, being a detention area,” he said. “You can see it that way, but obviously you need a place to house these people.”

The number of migrants coming in through Mexico has been trending sharply downwards – with last month’s crossings at the lowest they’ve been since January 2020

But the issue is still very much alive on the streets of cities like Chicago, far from the southern border.

It is one of several Democrat-run cities which have enacted so-called “sanctuary city” laws that limit local police co-operation with federal immigration authorities.

In response, since 2022, Republican governors in southern states like Texas and Florida have sent thousands of immigrants northward in buses and planes.

Tom Homan, who was chosen by Trump to lead border policy, told a gathering of Republicans in Chicago last month that the midwestern city would be “ground zero” for mass deportations.

“January 21st, you’re going to look for a lot of ICE agents in your city looking for criminals and gang members,” Homan said. “Count on it. It will happen.”

Many local politicians, including Chicago Mayor Brandon Johnson and the state’s governor, JB Pritzker, have continued to back sanctuary city laws, dubbed the “Welcoming City” ordinance here.

But the policy is not universally loved. In November, Trump made gains in many Latino neighbourhoods.

Recently, two Democratic Hispanic lawmakers attempted to change the ordinance and allow some co-operation by Chicago police with federal authorities. Their measure was blocked Wednesday by Johnson and his progressive allies.

For now, the worshipers at Lincoln United Methodist are making plans and watching carefully as they see how Trump’s plans play out.

“I’m scared, but I can’t imagine what people without papers are feeling,” said D Camacho, a 21-year-old legal immigrant from Mexico who was among the congregation at the church on Sunday.

Mexican consular officials in Chicago and elsewhere in the US have also said they are working on a mobile app that will allow Mexican migrants to warn relatives and consular officials if they are being detained and could be deported.

Officials in Mexico have described the system as a “panic button”.

Organisers at Lincoln United are also reaching out to legal experts, advising locals on how to take care of their finances or arrange childcare in case of deportation and helping to create identification cards with details of an immigrant’s family members and other information in English.

And several second-generation immigrants here said they were working to improve their Spanish, in order to be able to pass along legal information or translate for migrants being interviewed by authorities.

“If someone with five children gets taken, who will take the children in? Will they go to social services? Will the family be divided?” said Rev Emma Lozano – Reverend Tanya Lozano-Washington’s mother and a long-time community activist and church elder.

“Those are the kinds of questions people have,” she said. “‘How can we defend our families – what is the plan?'”