Donald Trump’s allies and some in the private sector have been quietly preparing to detain and deport migrants residing in the United States on a large scale, according to four sources familiar with the discussions.

And with the former president becoming the president-elect, those preparations are now expected to ramp up.

Immigration was a cornerstone of Trump’s 2024 campaign, and while he repeatedly touted promises of mass deportation on the trail – putting increased emphasis on interior enforcement compared to his 2016 fixation on the border wall – members of his orbit and some in the private sector discussed what that plan would look like, according to the sources.

Trump’s day one priority is to reinstate his former administration’s border policies and reverse those of President Joe Biden, senior Trump adviser Jason Miller told CNN.

Early discussions among Trump’s team have focused on removing undocumented immigrants who have committed crimes, a source familiar with the team’s preliminary plans told CNN. A key issue under consideration is how, when and if to deport immigrants who were brought to the United States as children, commonly known as Dreamers.

Targeting Dreamers would be a departure from the historically bipartisan support they’ve enjoyed. Some are temporarily protected by the Obama-era Deferred Action for Childhood Arrivals program that allows recipients to live and work in the US.

Tom Homan, who previously served as acting director of Immigration and Customs Enforcement, could potentially serve as one of the leads on immigration in the administration, sources said.

“It’s not gonna be – a mass sweep of neighborhoods. It’s not gonna be building concentration camps. I’ve read it all. It’s ridiculous,” Homan told CBS News in an interview that aired last month.

“They’ll be targeted arrests. We’ll know who we’re going to arrest, where we’re most likely to find ‘em based on numerous, you know, investigative processes,” he added.

Brian Hughes, a Trump senior adviser, said that when the president-elect returns to the White House, one of his priorities will be border security.

“President Trump won a landslide victory Tuesday because Americans embrace his common sense policy to secure our border and implement mass deportation for illegal migrants,” Hughes said.

Logistical challenges

Even before Tuesday night, some in the private sector who help provide services for detention spaces had already been in ongoing discussions about a potential second Trump term and are expecting planning to pick up, according to one of the sources.

One of the key elements of any plan to deport immigrants is detention space, which Democratic and Republican administrations have grappled with because of limited resources.

The federal government contracts with the private sector to build, operate and manage detention facilities, and works with county jails.

“There’s a small number of beds that are federally owned facilities. The rest of them are split between private detention facilities and county jails,” said John Sandweg, who served as acting director of Immigration and Customs Enforcement during the Obama administration. “There’s an ICE presence, but by and large the people operating the detention centers are employees of the contractors.”

There are a number of contractors the incoming Trump administration can lean on, including those who already have existing agreements with the federal government, making it a potentially easier process.

The hard part, current and former ICE officials said, is finding the money.

The average cost of apprehending, detaining, processing and removing one undocumented immigrant from the United States in 2016 was $10,900, according to figures released by ICE at the time. That year, ICE also said the average cost of transporting one deportee to their home country was $1,978. Since then, the costs have only grown.

ICE Enforcement and Removal Operations has generally been underfunded and has previously had to reprogram funds to expand detention space, especially during border surges. But there are limits to how much money can be reprogrammed, officials said.

“They would need to be aggressive to make sure they don’t have to reprogram,” one former senior ICE official said, citing the upcoming budget cycle. “If they want to accomplish the goals they’ve been talking about, they’d need orders of magnitude change.”

That also includes bolstering personnel, which has previously been a challenge for the agency.

“As far as the detention, they can canvas the existing contractors out there. They can move relatively quickly,” the former senior ICE official said, adding that deportations can be challenging with certain countries.

“Every country has different requirements for travel documents. Mexico and Central America, removals can happen quickly from the time they have order of removal. Most any other country it takes a lot longer,” they added.

ICE also has limitations in holding immigrant families – and is not responsible for holding unaccompanied migrant children; that responsibility lies within the Health and Human Services Department.

Mixed outlook at DHS

At the Department of Homeland Security, which is charged with immigration enforcement, officials are bracing for a seismic shift in immigration policy under the incoming Trump administration, prompting some interagency calls Wednesday as people prepare for the weeks ahead.

One Homeland Security official described the mood internally as a “mixed bag.” One of the questions top of mind among those in the department Wednesday was what will happen to Biden administration policies, like parole programs for certain nationalities that allowed beneficiaries to temporarily work and live in the United States.

“Shell shocked among the political,” another Homeland Security official said.

In his first days in office, Biden did away with many of the Trump administration’s controversial immigration policies. Now those policies may make a return.

For some at DHS, that comes as welcome news. Over the last three years, the Biden administration grappled with multiple border crises, garnering fierce criticism internally and externally among Republicans and Democrats.

Biden administration officials ultimately landed on a much harsher stance on the US-Mexico border that resulted in a dramatic drop in migrant crossings over recent months.

Still, some in the department’s immigration enforcement agencies welcomed Trump’s win.

“There is a lot of optimism and hope,” another Homeland Security official said.