A U.S. Border Patrol agent searches for immigrant footprints while looking through the U.S.-Mexico border fence in Yuma, Ariz., in March. Voters in Arizona will decide Nov. 5 whether to approve a ballot measure that would give local law enforcement the right to question, arrest and deport anyone suspected of having crossed the Mexico-Arizona border between legal ports of entry. (John Moore/Getty Images)
Former President Donald Trump has repeatedly promised to launch what he calls the “largest deportation program in American history” if reelected, targeting immigrants living in the United States without documentation — people whom he described in a rally this week as “vicious and bloodthirsty criminals.”
“I will rescue every city and town that has been invaded and conquered,” Trump pledged during the rally at New York City’s Madison Square Garden.
By law, immigration is a federal matter, and Trump has said he’ll federalize state National Guard troops, activate the military and build detention camps.
But experts and close Trump affiliates say state and local actions could affect any mass deportation program he might attempt.
States trying to criminalize unauthorized immigration across their borders could use those laws to begin detentions, for example. Sanctuary cities and states that refuse to assist Immigration and Customs Enforcement, known as ICE, the federal agency responsible for interior immigration enforcement and deportations, could look for barriers.
In fact, Trump’s proposed mass deportation plan won’t work without states, said Mark Morgan, who served under the 45th president as acting commissioner of U.S. Customs and Border Protection, the agency charged with securing the U.S. border and facilitating trade at ports of entry.
“It’s not going to be successful, as long as we have sanctuary cities and states that refuse to allow local and state police departments to work with ICE,” Morgan said in an interview with Stateline.
Over the past year, more than half a dozen red states have tried to address immigration independently. Arizona, Florida, Iowa, Louisiana, Ohio, Oklahoma and Texas have introduced or enacted measures that aim to criminalize unauthorized immigration into their state with severe penalties.
Many of these laws have been blocked from taking effect due to constitutional challenges over whether states can regulate immigration.
Arizona’s measure is on the ballot for voters to decide. If passed, it would grant local law enforcement the authority to question, arrest and deport people suspected of crossing the Mexico-Arizona border outside legal ports of entry.
It’s possible those actions could help federal authorities, but the key question is whether these state policies will even take effect, according to Kathleen Bush-Joseph, a lawyer and policy analyst with the nonpartisan Migration Policy Institute.
“One question is whether these measures would be allowed to come into force even, because there have been court challenges filed against some of these measures,” Bush-Joseph said.
Other states and cities have moved in the opposite direction, declaring themselves immigration sanctuaries. In those places, law enforcement officers may avoid questioning suspects or residents about their immigration status. Some jurisdictions may prohibit “287(g)” agreements, which allow ICE to deputize local law enforcement officers to enforce federal immigration law.
Although there is no universal definition of a sanctuary policy, state and local officials will generally limit their cooperation with federal immigration authorities but do not actively prevent federal officials from enforcing immigration laws.
Trump is considering withholding federal grants from police agencies that don’t cooperate if he is reelected, according to reporting this week by NBC News.
Trump made similar promises of mass deportations in his first presidential campaign, though deportations under his administration never exceeded 350,000 annually, according to data maintained by the U.S. Department of Homeland Security.
For comparison, former President Barack Obama carried out 432,334 deportations in 2013, marking the highest annual total on record.
SC voters rate the seriousness of problems in America in latest Winthrop poll
This time, however, some immigration experts say that a second, more experienced Trump administration may take a different approach.
“They’ve been preparing over the last three and a half years to get out of the gate running fast,” said César Cuauhtémoc García Hernández, an Ohio State University law professor and the author of the book “Welcome the Wretched: In Defense of the ‘Criminal Alien.’”
“We can expect to see them simply be more effective,” he said.
A second Trump administration, García Hernández told Stateline, would likely be better equipped to navigate the federal government’s bureaucracy and address any legal challenges that may arise in implementing its proposed immigration policies.
Morgan agreed, noting that the infrastructure to carry out deportations — from enforcement agents to immigration court — is already in place and simply needs to be used.
“You just take that basic foundation that already exists and you infuse it with what I call ‘a whole-of-government on steroids,’” said Morgan, who is a listed contributor to Project 2025, a 900-plus-age policy blueprint from the Heritage Foundation, a conservative think tank, for a potential second Trump administration.
“We’re not talking about anything new,” he said. “What we’re talking about is scale.”
Support for border security
Much of the public’s concern about immigration centers on crime and public safety, employment, voting integrity and the strain migrants place on social services and other government resources.
Many politicians have portrayed the situation at the southern border as “out of control.”
The Border Patrol recorded 101,790 encounters with migrants crossing the U.S.-Mexico border in September, according to a Stateline analysis of the latest available government data. This represents a 66% decline from the 301,981 encounters in December 2023, the highest monthly record to date.
Americans overwhelmingly say the federal government is doing a poor job of handling the migrant situation, according to some of the latest polling from the Pew Research Center. And if Trump wins a second term, some experts say public opinion may be on his side.
In February, 57% of Americans said that the large number of migrants seeking to enter the country is leading to more crime, according to a Pew survey. A June Gallup poll found that 55% of U.S. adults favor decreasing immigration levels.
Another Pew survey, conducted in August, found both differences and common ground on immigration policy among Trump and Harris supporters. Nearly 88% of Trump supporters favor mass deportations, compared with only 27% of those supporting Democratic Vice President Kamala Harris. Majorities in both groups, however, support stronger border security and favor admitting more high-skilled immigrants.
There are about 11 million immigrants living in the United States without legal authorization, according to national estimates. Their individual situations vary widely, from asylum-seekers — who may be granted legal status — to would-be workers searching for jobs, to people who entered on a tourist visa and overstayed.
Inflation, immigration worries push some Nevada Hispanics toward the GOP
Most have no criminal record, and some academic research suggests that immigrants are less likely to commit crimes than U.S.-born residents.
In July, ICE reported that there were 662,566 noncitizens with criminal histories on its national docket who had been released. Of those, 435,719 had been convicted of a crime, and 226,847 had pending criminal charges. Nearly 15,000 noncitizens with criminal convictions or pending charges remain in detention.
During her vice presidency, Harris was tasked with addressing the root causes of migration from Central America to stem the humanitarian crisis propelling families to travel north. She encouraged financial investment in El Salvador, Guatemala and Honduras, and though migrant numbers from those countries fell, they rose from other countries.
Now, Harris has said she’ll sign a bipartisan border security bill that stalled in the Senate this year after Trump urged Republicans to vote against it.
Trump’s mass deportation plan
A mass deportation of 1 million people per year could cost $88 billion annually, according to a report released in October by the nonpartisan American Immigration Council, a nonprofit group that advocates on behalf of immigrants. The money would be spent on an unprecedented expansion of law enforcement staffing, detention facilities, immigration courts and transportation capacity to move detainees.
The negative impacts — such as labor shortages, reduced tax contributions and the separation of mixed-status families — would be most pronounced in California, Texas and Florida, according to the group’s analysis.
Those three states, home to about 47% of the country’s immigrants living here illegally in 2022, would see 1 in every 20 of their residents deported.
Morgan dismissed the cost of mass deportation.
“It’s absurd that we’re talking about [how] our nation’s safety and national security has a price. Right now, the price is we’re paying with American lives,” he said. “It’s worth whatever it costs to safeguard our country’s safety and national security.”
During his rally in New York earlier this week, Trump once again pledged to ban sanctuary cities, which limit cooperation with federal immigration authorities, and to invoke the 1798 Alien Enemies Act to deport immigrants with criminal records.
The Alien Enemies Act allows the president to detain, relocate or deport the natives and citizens of a country considered an enemy of the United States during wartime.
Trump has also outlined plans to deploy the U.S. military and state National Guard troops for immigration enforcement. In 2024, at least 18 states have sent state police or National Guard troops to the border under both state and federal orders.
“If President Trump gets reelected, the border is going to be sealed, the military will be deployed, the National Guard will be activated, and the illegals are going home,” Stephen Miller, a former senior adviser and strategist behind Trump’s previous immigration policies, told a conservative podcast host earlier this year.
The military also could play a role in logistics, particularly in detention and transportation, according to Morgan. Military installations across the country could provide space for detaining immigrant families, he said.
“We’re going to detain people as families, and we’re going to move them as families,” Morgan said.
Who would Trump deport and how?
Of the estimated 11 million immigrants living in the United States illegally, about 1.3 million have already been issued removal orders but remain in the country, according to Bush-Joseph, the policy analyst with the Migration Policy Institute.
“There’s just not enough Immigration and Customs Enforcement agents to be arresting and removing everyone,” Bush-Joseph told Stateline. “Some countries won’t take their nationals back.”
People with existing removal orders could be targeted first, along with the hundreds of thousands of immigrants who already have been convicted of a crime, said Jessica Vaughan, the director of policy studies at the Center for Immigration Studies, a national research and advocacy group that favors reduced immigration.
Haitian immigrants find new footholds, and familiar backlash, in the Midwest, South
“That’s low-hanging fruit for ICE,” Vaughan said in an interview with Stateline.
And while people with criminal convictions could be the Trump administration’s top priority in a second term, Morgan told Stateline that “no one will be off-limits.”
Obama had enacted a policy prioritizing removals of people who had been convicted of a serious crime, but Trump ended that approach as soon as he took office in 2017, saying he wanted enforcement against all immigrants who could be removed.
An analysis released this week by the libertarian Cato Institute found Trump’s policy deported fewer dangerous criminals than Obama’s, and that his mass deportation scheme would “shift focus away from immigrants who do commit crimes.”
There are also hundreds of thousands of legal beneficiaries of temporary programs who could be affected by mass deportations.
More than 860,000 people from 16 different countries, including Afghanistan, Ukraine, Syria, Venezuela and Haiti, benefit from “temporary protected status,” according to the National Immigration Forum, a nonprofit advocacy group.
We can expect to see the Trump administration do what they tried to do the first time around, which is to end TPS for citizens of several countries.
– César Cuauhtémoc García Hernández, Ohio State University law professor
The secretary of Homeland Security can cancel a country’s TPS designation but must decide whether to extend or terminate it at least 60 days before the expiration, based on conditions in the country.
The Trump administration attempted to end TPS for Haiti and several other countries in 2017, but lawsuits blocked this policy change until the Biden administration ultimately reversed it.
“We can expect to see the Trump administration do what they tried to do the first time around, which is to end TPS for citizens of several countries — Haiti being at the top of that list right now,” said García Hernández, the Ohio State University law professor.
Just over 535,000 immigrants who arrived as children when their parents crossed the border illegally benefit from the Obama-era program Deferred Action for Childhood Arrivals, or DACA, according to U.S. Citizenship and Immigration Services. Trump attempted to abolish the program in 2017, but the Supreme Court blocked him from ending it in 2020.
A year later, a U.S. District Court judge in Texas ruled that DACA is unlawful, sparking a multiyear effort in which the Biden administration has repeatedly appealed rulings against the program. In early October of this year, the 5th Circuit Court of Appeals heard arguments on DACA, and a decision on whether it can continue or must end could come at any time.
Changing demographics and the political calculus of anti-immigrant rhetoric in swing states
At a rally in Tucson, Arizona, in late October, U.S. Sen. J.D. Vance of Ohio, Trump’s running mate, did not rule out deporting DACA recipients.
“We also have to deport people, not just the bad people who came into our country, but people who violated the law coming into this country. We’ve got to be willing to deport them,” Vance said in response to a reporter’s question about deporting DACA recipients. Vance did not specifically address DACA recipients.
Additionally, nearly 3 million asylum applications are pending in court and with U.S. Citizenship and Immigration Services, according to Bush-Joseph.
To find immigrants to deport, much of the enforcement will likely come from ICE’s Enforcement and Removal Operations task force, in addition to relying on local and state law enforcement agencies, according to Morgan.
The U.S. Customs and Border Protection’s National Targeting Center may also create “targeting packages” to help identify immigrants living in the country without legal authorization, Morgan said, adding that the FBI and the U.S. Marshals Service could also participate.
“It’s just like any other law enforcement agency that tracks down U.S. citizens. There’s no difference,” Morgan said.
Like SC Daily Gazette, Stateline is part of States Newsroom, a nonprofit news network supported by grants and a coalition of donors as a 501c(3) public charity. Stateline maintains editorial independence. Contact Editor Scott S. Greenberger for questions: info@stateline.org. Follow Stateline on Facebook and X.