In 2006, when I first began researching deportations, George W. Bush was president and quietly building a deportation machine in the Department of Homeland Security. Outside of small activist circles, few Americans knew that deportations had been rising since 1996 due to legislation signed by President Bill Clinton. Nor could anyone then have imagined that the next president would be a Democrat, the son of a Kenyan immigrant, and would make Bush look like a piker when it came to record-high deportations. Nor, for that matter, would anyone have dreamed that deportation would become a—possibly the—signature issue of the 2016 presidential campaign.

And yet, all of this and more has come to pass in a blistering season of demagoguery, nativism, and outright racism. As again would have been unimaginable a mere decade ago, Republican front-runners Donald Trump and Ted Cruz have both promised to deport every last one of the estimated 11 million undocumented migrants in the United States, the whole lot of them, while as a bonus banning Muslims from the country. Trump gave his particular proposals a special twist by labeling Mexicans coming across the border as “rapists,” and immigrants more generally as “snakes.”

On the issue of deportations, the Republican presidential hopefuls differ in only one tiny way: Trump claims he will allow the “really good” immigrants to return, while Cruz wants to get rid of every last undocumented immigrant permanently.

To put all this in perspective, here’s the crucial thing you need to understand: With such “proposals,” we have been plunged into a grim fantasyland. You can be guaranteed that neither of these men has spent a serious moment considering what it might really mean to deport those 11 million actual human beings. Behind such a program there can be no real plan, because it would prove both unaffordable and unworkable (leaving aside its utter inhumanity).  Undoubtedly, neither Trump nor Cruz cares about the details of all this, since the point is to arouse deep fears of loss and visceral betrayal in the white working-class voters they want to attract.  But it’s worth taking their proposals seriously enough to ask a relatively straightforward question: Is it feasible to deport 11 million people?

Deporter-in-Chiefs?

Any plan to deport all undocumented migrants would involve an inconceivably massive expansion of the current deportation program, which since 1996 has already experienced significant growth. The highest number of people ever deported from the United States in a given year is 237,941.  That was the number of “interior removals” reported by the Department of Homeland Security’s Immigration and Customs Enforcement (ICE) in 2009. A removal, by the way, is a deportation that involves a court process, while an interior removal is a deportation involving a person who is arrested inside the United States and is not a recent border-crosser.

Keep in mind that those 237,941 undocumented immigrants expelled from the country represented a far higher number of deportations than had ever previously been experienced. Before 1995, there were never more than 50,000 total removals (including people caught crossing the border). Only in 2003 were figures for interior and border removals reported separately, at which time there were 30,000 interior removals. A concerted effort in the years that followed would translate into a sevenfold increase in the number of interior removals during the Bush presidency.

When President Obama took office in 2009, he topped the Bush numbers, overseeing record deportations and keeping interior removals steadily above 200,000 until 2012.  Then those numbers began to decline, dropping to a still hefty 69,478 interior removals in 2015. For his early deportation record, Obama earned the title of “deporter-in-chief” from immigration activists, as well as the ire of the Latino community. Perhaps due to pressure from that community, he has in recent years rolled back deportations, in addition to issuing an executive order that grants temporary authorization to stay and work in the United States to immigrants who came here as children. He also issued another executive order that would grant the same protections to their parents, although it is still held up in the courts.

Now, for the future: the promise to deport all 11 million undocumented migrants in, assumedly, two four-year presidential terms would mean the deportation of 1,375,000 people annually, or six times that all-time high of 237,000. In other words, Donald Trump or Ted Cruz would have to almost match Bush’s sevenfold increase in deportations on a truly monumental, essentially inconceivable scale. The more realistic question in the grim world of deportations would be: Could one of them even get back to the 237,000-a-year figure? It’s far from clear that any president could actually restore such record-high deportation rates today (forget the promise of millions).

As it happens, ramping up deportations again would require cooperation from local criminal law enforcement, which is unlikely. In reality, local police departments have been moving away from such cooperation over the past few years, in part due to criticism that such programs encourage racial profiling while diminishing trust between communities and the local police.

The dramatic increase in deportations under President Bush relied heavily on increased cooperation between local police and ICE, due to real limitations on the ways in which immigration laws can be enforced. Whereas local police officers are empowered to patrol the streets and arrest people suspected of committing crimes, immigration law–enforcement agents are not authorized to pull people off the streets simply because they suspect they might be undocumented. An important reason for this: There is no way you can figure out a person’s immigration status simply by looking at them.

Only Customs and Border Patrol (CBP) agents are authorized to rely on “Mexican appearance” when deciding whom to interrogate and they can only operate up to 100 miles from the border. Interior immigration enforcement is mostly carried out by Immigration and Customs Enforcement agents with the help of local police officers who can indeed inquire about someone’s immigration status, but only after such a person has been stopped on reasonable suspicion of committing a crime.

There are currently about 5,000 ICE agents in the country. Their capacity, with limited cooperation from local law enforcement, seems at the moment to be about 70,000 deportations a year, as evidenced by 2015 numbers. To get those deportations back above 200,000 would involve gargantuan and expensive efforts and a restoration of the frayed relationship between ICE and local police departments.

Home and Workplace Raids

How, then, are 5,000 ICE agents, or even 15,000—the number Donald Trump wants—going to deport more than a million people annually? In reality, there is no way that those numbers would be enough to arrest and expel the nearly 4,000 people a day, or 1,460,000 people a year that Ted Cruz implies he would reach in his presidency.

It may seem like 5,000 agents should be capable of arresting at least one person each a day and so meet those goals. But the process is simple only in a Trumpian fantasy world.  In the real world, locating and then arresting the undocumented is anything but a straightforward process. After all, ICE agents can’t go around interrogating people to find out if they are undocumented and then sweep them off the streets. They can, however, arrest people in their homes—if they have a warrant.

Once an investigation is completed and such a warrant has been issued, an ICE raid on the home of a suspected undocumented migrant usually involves about a dozen agents working through the National Fugitive Operations Program that has come under harsh criticism for its remarkable inefficiency.  To have such a home raid described is to begin to understand why such raids tend to work out so poorly.

In February 2010, Maximo, a Dominican citizen who lived in Puerto Rico and experienced just such a raid, described the process to me. He shared an apartment in San Juan with two other men, a Venezuelan and a Puerto Rican.  Early one morning, they heard loud banging on the door. Maximo tried to sleep through it, but it only got louder. Finally, he got up. Before he could answer the door, however, the ICE agents decided to break it down and he found himself surrounded by several of them, guns drawn, demanding to see all of the occupants of the apartment. The three men were then ordered to sit on the floor. Finally, Maximo was given his clothes and allowed to get dressed.

When asked for identification, he gave them his Dominican passport. Was he, they then asked, in the country illegally? He admitted that he indeed was, which led to his arrest and dispatch to an immigration detention center. There, he signed a voluntary departure order and two days later was deported to Santo Domingo. In other words, that day’s work for at least a dozen officers led to the deportation of a single Dominican as his housemates were legal permanent residents. This is typical of the kinds of “successes” that ICE agents have.

Among other things, the next president could revisit the worksite enforcement strategies implemented during the Bush years to find undocumented workers. Such worksite raids, however, have proven even less effective and efficient than home raids.

Consider the 2008 Postville raid in Iowa, at the time the largest of its kind ever. Start with the fact that it took almost a year and a half of investigation and planning to pull off. In December 2006, federal agents began to look into a worksite enforcement operation in Postville, a town with 2,273 inhabitants, 968 of whom worked at Agriprocessors, a kosher slaughterhouse and meat-processing plant. On Monday, May 12, 2008, the plan became a reality as 900 agents descended on the town. Cooperation among several federal and local agencies was necessary for this to happen. In all, 389 immigrant workers were arrested, though only half of them were eventually deported. In other words, ICE spent a year and five months working on a case that required almost 1,000 agents on the ground and eventually resulted in fewer than 300 deportations.

So let’s put this simply: There is no quick and easy way to deport millions of people from the United States, in part because we are a nation that values individual rights and requires at least some semblance of a process before a person is uprooted from his or her home or workplace. It is not within the purview of the executive branch to topple existing laws and judicial processes in order to carry out the mass removal of a significant segment of the population.

In sum, President Obama has done about as much damage as is presently possible to undocumented migrants and their families within these legal and judicial constraints. Trump’s and Cruz’s claims that they will do significantly more are baseless—unless the American system were to be changed in fundamental ways (and even then, achieving their goals would prove unlikely in the extreme).

Walls and Other Fantasies

Add to all of this an even greater and more literal fantasy edifice: Donald Trump’s wall. That future 80-foot competitor to the Great Wall of China is slated to cover the 2,000-mile-long southern border, sport all the latest in surveillance technology, and (as The Donald regularly reassures audiences at his rallies) be paid for by the Mexicans. As it happens, Mexican President Enrique Peña Nieto, who recently compared Trump’s language to Hitler’s, disagrees. He’s made it abundantly clear that he would never comply with such a demand, while the previous Mexican president, also citing Hitler, has simply termed the very idea “stupid.” Felipe Calderón, Peña Nieto’s predecessor, said the Mexican people won’t “pay any single cent for such a stupid wall!”

In Trump’s far-fetched proposal lurks a crucial irony of our moment: Mexicans are no longer emigrating in large numbers to the United States. Over the past decade, more Mexicans have returned from the United States than headed illegally for it.  Undocumented border crossings from Mexico have, in fact, been falling for the last 15 years, in part thanks to a sharp decline in the fertility rate in that country and the consequent lack of demographic pressure for people to leave.

And don’t forget that the wall would be a staggering infrastructure project. It would, for instance, require 10 percent of all the cement produced in the United States in a year. And then there’s the issue of the price. It is estimated that just fencing in the full 2,000-mile border would cost up to $25 billion, or a quarter of what the federal government spends on infrastructure annually. An 80-foot, high-tech wall would cost far more. And let’s not forget that infrastructure in the United States is falling apart: Highways are crumbling and mass-transit systems are in desperate need of repair and modernization. Imagine the federal government, spurned by the Mexicans, spending tens of billions of dollars on such a wall when Amtrak, for example, is barely scraping by with an annual budget of $1.6 billion, while other developed countries are leaving us in the dust with 200-mile-per-hour bullet trains.

All this means that the proposals to “build a wall” and “deport them all” that have animated this election season are quite fantastical. And then there’s the irony that such plans come from a political party that has long criticized government spending and waste. On wasting money, we’re talking textbook cases here.

In short, taken on their own “merits,” the numbers don’t add up. The costs would be tremendous. The disruption to American life in which the undocumented play a little noticed but crucial role would be far more unsettling than any of Donald Trump’s or Ted Cruz’s admirers imagine, and no wall or deportation program will protect them from the actual forces decimating their lives (and life spans). In fact, looked at piece by piece, in a purely practical way, the present deportation debate, which has proven extremely effective in raising the temperature of the political moment, is simply the essence of the demagogue.

Should Donald Trump or Ted Cruz win the presidency, they are guaranteed to make life hell for millions of undocumented human beings living in and working extremely hard in this country, and their plans would fail dismally—but that failure would undoubtedly prove to be a horror all its own.