President-elect Donald Trump identified a Colorado city as the launching pad for what he dubbed “Operation Aurora,” the start of what he promised to be the largest mass deportation in American history.

While the city’s mayor expressed doubts that Trump would follow through with his promise, a councilmember said the next president’s words need to be taken seriously.

“Operation Aurora,” said Councilmember Danielle Jurinsky, “is coming.”

What “Operation Aurora” and mass deportations would look like remains to be seen. The Trump administration faces potential legal hurdles — the ACLU and other groups have been preparing for protracted court battles in anticipation of a second Trump presidency — and logistical ones, particularly since such a campaign, to be effective, would need the cooperation of local governments.

The latter is unlikely in Colorado, a “sanctuary” state.

No legal definition of a “sanctuary” city or state exists, but, broadly speaking, it refers to a community that expressly refuses to cooperate with federal authorities on enforcing immigration laws. Back in 2019, Colorado adopted a law whose provisions fall under the broad outlines of what constitutes a “sanctuary” state. Several Colorado counties have sued the state over the law.  

In addition, Colorado’s most populous city — Denver — is also a “sanctuary” city.

Critics argued that the mass deportation plan would be costly, while supporters maintained that it’s not only feasible but necessary, particularly because Trump vowed to fight illegal immigration, a top issue for American voters, during his campaign.  

Supporters also argued that illegal immigration enforcement in America’s interior cities, along with strict border controls, would serve as a deterrent, much as Denver’s offer of free housing and transportation drew tens of thousands of immigrants to the city over a two-year period.   

Why is it called “Operation Aurora”?   

At a rally last month in Aurora, Trump blasted the Biden administration’s handling of illegal immigration, which he contended had contributed to the gang problem in Colorado’s third-most populous city.

“We are a country under tremendous distress,” Trump said. “We will send elite squads from ICE to deport every single gang member.”

Long before reports of a Venezuelan prison gang infiltrating three apartment complexes in Aurora became international news, the arrival of hundreds of thousands of immigrants in America’s interior cities brought to the crisis beyond the country’s border states.

In Colorado, some 43,000 immigrants, who illegally crossed the southern border, arrived in Denver since December 2022. About half have stayed — the equivalent of adding roughly 21,500 people, or a city the size of Golden, in less than two years.

The vast majority are from South and Central America, particularly Venezuela. 

The sudden influx left officials scrambling to respond to hungry immigrants arriving in frigid conditions — often wearing sweatshirts and slippers in the snow — with nowhere to go.

Denver officials decided early in the crisis to provide — largely at the expense of taxpayers — temporary shelter and onward travel for newly arriving immigrants.

That has cost more than $75 million.

Originally, officials believed the draw was Denver’s proximity to Mexico and its status as a “sanctuary city.” But Texas officials in El Paso believe that the city’s offer of shelter and onward travel — while good intended — actually made Denver a magnet for immigrants.

“There’s a pull factor created by this, and the policies in Denver for paying for onward destinations,” said Irene Gutiérrez, executive director of El Paso County Community Services.

As Denver felt the brunt of the influx, officials in Aurora, Colorado Springs and Douglas County reaffirmed their “non-sanctuary” status in response to growing public concerns over immigration enforcement and safety.

Those safety concerns were soon personified in a Venezuelan prison gang known as Tren de Aragua, or TdA.

The trans-national gang has a diverse criminal portfolio that includes drug and human trafficking — particularly immigrant women and girls, kidnapping, extortion, and money laundering.

Aurora police have known for about a year that gang members are known to “infiltrate migrant caravans headed for the United States,” according to an internal, special bulletin distributed to officers on Oct. 5, 2023.

The public didn’t become aware that TdA gang members were operating in the Denver metro area until three months ago.

In August, city officials shuttered the Aspen Grove apartment complex, citing a litany of long-standing health and safety violations that included, among others, rodent infestations, sewage backups and trash pileups and a lack of electricity. The unprecedented move to shutter an apartment complex for code violations left about 300 people — mostly immigrants — homeless.

Aspen Grove is a 99-unit complex owned by Brooklyn-based, CBZ Management, which owns 10 other properties in Colorado, including Whispering Pines and The Edge at Lowry in Aurora. The owners have long insisted — through a Florida PR firm and their attorney — that TdA gang members had taken control of their Aurora properties.

Initially, Aurora officials publicly denied the gang’s footprint for its decision to shutter the apartment complex, blaming the rapidly deteriorating conditions on absent landlords. But internal police emails, an investigation by the lender and letters to state and city officials showed the authorities had been aware of the presence of the gang for about a year.

These documents also showed Aurora officials were keenly aware of the optics and struggled with the city’s response.

Meanwhile, the police had grown wary of the gang. With TdA members claiming to have more than 200 people working for them, officers began to warn one another about the gang.

Officials began walking back their statements after a video of armed men barging into apartment units surfaced and a cache of letters from a law firm representing CBZ Management — written a month before the federal government acknowledged TDA had extended its tentacles into Denver — became public.

By September, Aurora and its troubles with the Venezuelan gang have already caught the eye of Trump. That month, he announced he would visit the Colorado city.

“I’m going to Springfield, and I’m going to Aurora,” Trump said.

And during his rally in the city last month, he said that, under “Operation Aurora,” the federal government would expedite the removal of “savage gangs” living in the country illegally.

Donald Trump’s leverage

Trump’s selection of longtime advisor and border hawk Stephen Miller as deputy chief of policy and former U.S. Immigration and Customs Enforcement official Tom Homan as “Border Czar” signals his administration is serious about mass deportations.

Here’s how that might unfold.

Trump is expected to mobilize agencies across the U.S. government to help him in the campaign, building on efforts in his first term to tap all available resources and pressure so-called “sanctuary” jurisdictions to cooperate, according to six former Trump officials and allies.

Trump backers, including some who could enter his second administration, anticipate the Republican president-elect will call on everyone from the U.S. military to diplomats overseas to turn his campaign promise of mass deportations into a reality. The effort would include cooperation with Republican-led states and use federal funding as leverage against resistant jurisdictions.

Trump’s running mate, JD Vance, estimated that the campaign could remove a million people per year.

A deportation operation targeting millions would require more officers, detention beds and immigration court judges.

Homan, the former acting director of U.S. Immigration and Customs Enforcement and incoming “Border Czar,” said in a late October interview that the scale of the deportations would hinge on potential officers and detention space.

“It all depends on what the budget is,” he said.

While the incoming Trump administration could benefit from experience gained during his first term, it could again encounter resistance from ideologically opposed government employees, including officers that screen immigrants for asylum.

The American Civil Liberties Union and other advocacy groups have been preparing for court battles if Trump again tests the bounds of his legal authority.

Lee Gelernt, an ACLU attorney who led the fight against Trump’s contentious family separation policy, said more than 15 lawyers focused on immigration with the organization’s national office spent the year readying for the possibility of a Trump return.

“We definitely need to be coordinated and have more resources, because I think they will come in much more prepared,” Gelernt said.

The State Department in particular could be one place where Trump acts more aggressively than during his first term, several Trump backers said.

A key factor will be whether other countries will accept their citizens, an issue Trump faced with limited success during his first term. The Trump administration also struggled at times to convince other nations in the region, including Mexico, to take steps to stop migrants from moving toward the U.S.-Mexico border.

Ken Cuccinelli, former acting deputy secretary of the U.S. Department of Homeland Security under Trump, said the State Department was a “roadblock” for immigration enforcement and that aggressive appointees would be key.

Christopher Landau, a former U.S. ambassador to Mexico from 2019-2021, recently said he was frustrated with the reluctance of some U.S. diplomats to tackle immigration enforcement.

“Nobody really thought that was their problem,” Landau said in an October panel discussion by the Center for Immigration Studies, which describes itself as having a “pro-immigrant, low-immigration vision, which seeks fewer immigrants but a warmer welcome for those admitted.”

About half of ICE’s 21,000 employees are part of its Homeland Security Investigations unit, which focuses on transnational crime, such as drug smuggling and child exploitation, rather than immigration enforcement. Several Trump allies said the unit would need to spend more time on immigration.

Stephen Miller, the architect of Trump’s first-term immigration agenda, said in 2023 that National Guard troops from cooperative states could potentially be deployed to resistant states to assist with deportations, which would likely trigger legal battles.

Trump also plans to use a 1798 wartime statute known as the Alien Enemies Act to rapidly deport alleged gang members, an action that would almost certainly be challenged in court.]

Colorado officials express skepticism  

Aurora Mayor Mike Coffman told The Denver Gazette he is skeptical that Trump’s vows will come to fruition.

“I think that President-elect Trump has a history of saying things at his rallies with no intention of ever carrying them out once in office,” the mayor said. “I would put ‘Operation Aurora’ in the same category as ‘we are going to build a wall and Mexico is going to pay for it.'”

And if Trump goes through with the plan, Coffman said it would be a “political error.”

“If he went through with it, he would be making an unforced political error with no upside,” Coffman said. “His exaggerated claims, that Aurora has been ‘taken over’ by Venezuelan gangs and is being ‘occupied,’ simply are not true.”

Aurora city spokesperson Ryan Luby did not specifically say whether the city would comply with a mass deportation program. He said both the city and its police department “focus on enforcing state and local law.”

“As we always have, we will work with our federal partners and follow federal law and directives as they apply to our community,” Luby told the Denver Gazette.

In a public safety committee meeting of the Aurora City Council on Thursday, Councilmember Danielle Jurinsky, who who has talked about the Venezuelan gang’s activities in her city with local and national media organizations, said Trump’s deportation plan is happening.   

“I hope we are preparing for that,” she said. 

“(There) seems to be a disconnect” between the city and the Trump administration, Jurinsky said, adding she hopes the city is “taking it seriously.”

In Aurora’s neighboring city, Denver Mayor Mike Johnston told Denver Gazette news partner 9News that he, too, isn’t sure Trump will actually follow through on his promise.

If he does, Denver won’t cooperate, he said. 

“We are not going to open up our city boundaries to any state or federal agents that come in and take people out of their homes and try to deport them without cause, so we think that we are prepared to work together to make sure that folks are successful,” Johnston told 9News. “We don’t know what the president has planned. We will be happy to partner on things that make sense, but we are not going to partner on things we think are an infringement on people’s rights.”

At the peak of the border crisis spilling into Denver, Johnston had embraced the role of de facto spokesperson for interior cities grappling with the tens of thousands of immigrants the local governments have fed, housed and transported. Johnston did not specifically talk about stopping the flow of immigrants into Denver. Instead, the mayor sought strategies to ease the burden on his city.

The mayor notably stayed clear of talking about “border security,” an omission that underscored the ideological lenses with which Democrats and Republicans often view the border crisis.

Meanwhile, Colorado Gov. Jared Polis announced the creation of a new group called Governors Safeguarding Democracy, which could serve as a coordinated platform for Democratic states to oppose Trump policies on everything from immigration to the environment.

“We founded (the group) because we know that simple hope alone won’t save our democracy,” Polis said on a conference call. “We need to work together, especially at the state level, to protect and strengthen it.”

Whether the new Democrat-led group will have much success is unclear. Democratic-led states repeatedly fought against Trump policies in his first administration, but he still managed to push through his agenda on everything from energy policy to immigration restrictions.

Colorado’s ‘sanctuary’ laws

Trump’s mass deportation program will likely run into barriers along state lines, particularly in Colorado. 

A 2023 law that went into effect in Colorado in January restricts the ability of state and local governments to make agreements with federal immigration officials over the detention of immigrants who are unlawfully staying in the country. 

More notably, a 2019 law expressly forbids a law enforcement officer from arresting or detaining an individual based upon a “detainer request.” The law also prohibits a probation officer from providing information about an individual to federal immigration authorities.

An immigration “detainer” is a notice issued to federal, state and local law enforcement agencies informing the latter that ICE intends to assume custody of an individual who is no longer subject to the former’s detention.

ICE said a detainer serves several functions, including requesting information from a local enforcement agency about a person’s impending release and asking the local enforcement agency to maintain custody of the person for a period not to exceed 48 hours — excluding Saturdays, Sundays, and holidays — to provide ICE time to assume custody.

State laws also prevent state judicial officials from sharing information with federal immigration officials.

In April, the counties of El Paso and Douglas filed a lawsuit against the state over its “sanctuary” statutes, calling them “illegal and unconstitutional” and arguing they violate the Colorado Constitution’s provisions on intergovernmental relationships and distributions of powers. 

A mass deportation such as the one Trump is contemplating has never been undertaken in the United States.

Since 2010, the U.S. has removed — on average — fewer than 300,000 unauthorized immigrants with a peak in the Obama administration of 432,448 immigrants in 2013, according to data from the U.S. Department of Homeland Security.

The number of annual removals has been dropping ever since.

According to the Pew Research Center, an estimated 10.7 million immigrants were unlawfully living in the U.S. in 2016.

Colorado alone had 160,000 unauthorized immigrants that, but this estimate does not account for the nearly 43,000 immigrants — about half of whom have stayed — who have arrived over the past two years.

University of Colorado Boulder Law Professor Violeta Chapin, who runs the Criminal and Immigration Defense Clinic, said the reality of the move would cost “hundreds of billions of dollars.” At least one estimate by The American Immigration Council last month put the price tag on such a mass deportation effort at a “conservative” $315 billion.

Those costs include locating, detaining and processing through immigration courts millions of unauthorized immigrants, she said. 

She also questioned the viability of Trump’s promise.

“We’ve never been able to deport more than half a million or three-quarters of a million a year — ever,” Chapin said.

Trump’s allies, meanwhile, see deportations as necessary, arguing that Democratic policies have favored immigrants unlawfully staying in America over the country’s citizens. 

“Illegal immigrants deserve only one thing: a one-way ticket back home to wherever they came from,” U.S. Rep. Lauren Boebert, a Republican from Colorado, earlier said on X. “They don’t deserve free housing, free healthcare, or even free refills!”

“Operation Liberate Aurora,” she recently tweeted.  

Reporters from Reuters contributed to this article.