As Donald Trump prepares for his return to the White House on January 20, immigrant rights groups are bracing in anticipation of a crackdown promised by the president-elect and his allies.

With hardliners like Stephen Miller and Tom Homan selected for key positions related to immigration, humanitarian groups in both the United States and Mexico say they are determined to press forward with their work, but have no illusions about the challenges ahead.

“I’m expecting it to be exponentially worse than the first term,” Erika Pinheiro, director of the immigrant rights group Al Otro Lado, told Al Jazeera.

“I think political persecution is going to be supercharged,” she added, saying she believes rights groups will face spurious legal challenges meant to take up time and resources.

Interviews, campaign speeches and policies floated by Trump and his advisers suggest an ambition to fundamentally reshape the US immigration landscape, with a blitz campaign of mass deportations as well as potential attacks on longstanding rights such as birthright citizenship.

While rights groups say they are prepared to challenge such efforts, they also concede that a second Trump administration will be bolstered by a popular election victory and Republican majorities in Congress, along with experience gained from battles on immigration during Trump’s first term in office.

Mass deportations

Several immigrant rights groups that spoke with Al Jazeera said that not all of Trump’s plans for a second term are clear, but all agreed that one effort, in particular, would be front and centre come January: a campaign to round up and deport large numbers of undocumented people living in the United States.

Advisers such as Miller, an architect of policies such as the ‘Muslim Ban’ and a “zero-tolerance policy for criminal illegal entry” – which intentionally separated migrant parents from their children during Trump’s first term – have suggested that the number of undocumented people could be in the millions.

“He [Trump] seems far more prepared than in his first term,” Vicki Gaubeca, associate director of US immigration and border policy at Human Rights Watch, told Al Jazeera.

“He’s stated over and over again that his day one agenda will be to carry out mass deportations, so we’re fully expecting to see that,” she added, noting that it remains to be seen how the administration will muster the resources necessary to carry out such a large-scale plan.

Miller, who was recently named as Trump’s deputy chief of staff, has previously said that such an effort would include using the armed forces and national guard units and will come in the form of a blitz meant to disorient rights groups. Trump himself recently stated that a national emergency would be declared and the military mobilised to help facilitate deportations.

“Any activists who doubt President Trump’s resolve in the slightest are making a drastic error,” Miller told The New York Times in November 2023, adding that Trump would use a “vast arsenal” of federal powers to carry out sweeping deportations.

“The immigration legal activists won’t know what’s happening,” he added.

Legal concerns

Several activists and organisations also expressed concern that humanitarian work at the border and assistance for undocumented people could itself come under growing pressure.

“We are not terrorists, we are not promoting irregular migration. We’re trying to help people and save lives. Putting water in the desert is not a crime. Humanitarian aid is not a crime. But they can turn it into one, if they choose,” Dora Rodriguez, a humanitarian worker who does work on both sides of the border near Tucson, Arizona, told Al Jazeera.

“But these are my morals. These are my duties,” she added. “You have to find the courage.”

Others said that a series of investigations launched by Texas Attorney General Ken Paxton against immigrant rights groups such as the Las Americas Immigrant Advocacy Center could serve as a template for increased prosecution.

Paxton also led an effort to shut down a migrant shelter in El Paso, arguing that offering assistance to people suspected of being undocumented was equivalent to human smuggling.

“I’m looking to Texas as a premonition of what’s coming,” Pinheiro, the director of Al Otro Lado, said. “Groups that work on both sides of the border are being accused of facilitating migration.”

“I expect some of us will face criminal prosecution in the coming years. We’re very careful to follow the letter of the law. But these are bogus lawsuits. What can you do to prepare for that?” she added.

Activists in Arizona, one of four US states that share a border with Mexico, say they are also concerned. During the first Trump term, a humanitarian volunteer named Scott Warren with the group No More Deaths faced felony charges for providing assistance to undocumented people at an aid station in the desert.

The group sets up such facilities to offer food, water and medical assistance to stranded migrants whose lives are often at risk after travelling through inhospitable terrain for days at a time. Warren was acquitted in 2019, but activists fear that such efforts may soon return.

“Under Trump, we expect Border Patrol and [anti-immigrant] militia groups to be more emboldened than ever and to operate with more impunity than ever, as we saw under Trump’s first term,” No More Deaths said in a statement shared with Al Jazeera. “But we will not back down from our mission and our work.”

‘You need to prepare yourselves’

Rights groups are trying to ready themselves for Trump’s return to the White House, and advise members of their communities to do the same.

“We’re gearing up for whatever may come,” Father Pat Murphy, director of the Casa Del Migrante shelter in the Mexican border city of Tijuana, told Al Jazeera.

He hopes the Mexican government will do more to help humanitarian organisations on the Mexican side of the border overwhelmed by the strain that would accompany mass deportations.

“There are always going to be people who are trying to come. They feel they have no alternative but to try to cross into the US,” he added. “Some make it, others don’t.”

Rodriguez, the humanitarian worker in Arizona, said she has seen an increase in anxiety among families in the US with undocumented members.

In a recent television interview, Homan, the border tsar, was asked if there was any way to conduct mass deportations without splitting up families. Many immigrant families are “mixed status”, meaning that some may have legal status while others may not.

“Of course there is,” said Homan. “Families can be deported together.”

“There are people who have been here for 20 or 30 years and have no criminal records, and they still feel terrified that they will be taken away from their families,” said Rodriguez. “We are telling people in our communities, ‘You need to know your rights, you need to know what to do if a family member is arrested, you need to prepare yourselves.’”