The screen fills with images of migrants dodging highway traffic. “They keep coming,” says a narrator. “The federal government won’t stop them yet requires us to pay billions to take care of them. … Enough is enough.”

This message might sound familiar, but it isn’t new. It’s a 1994 campaign ad in support of Republican politician Pete Wilson’s run for reelection as California governor.

At the time, California was experiencing its worst recession in decades. Although immigrants living in the state illegally did not cause California’s economic crisis, they were a convenient scapegoat. By blaming immigrants for California’s financial woes, Wilson turned his faltering campaign around and won reelection in November 1994.

Thirty years later, the United States is in a similar political moment, with many Americans worried about the cost of living and immigration.

President-elect Donald Trump has repeatedly – and misleadingly – blamed immigrants for crime, high housing costs and other problems. He is promising to quickly close the U.S. southern border and deport the nearly 12 million immigrants without legal authorization to remain in the country.

As a scholar of migration in the Americas, my research shows that Trump’s approach is unlikely to stop migrants from trying to enter the U.S. but very likely to enrich criminals. Migrants will keep fleeing desperate circumstances under even more treacherous conditions that leave them vulnerable to exploitation by criminal groups.

A few months after Wilson’s campaign ad hit the airwaves, the U.S. Border Patrol issued its strategic plan for 1994 and beyond.

In this plan, the Border Patrol proposed a strategy called “prevention through deterrence” that was designed to make illegal entry across the southwest land border so risky that potential migrants would decide to stay home.

By concentrating border enforcement in the urban areas where most migrants were trying to cross, the plan aimed to force them “over more hostile terrain” in the desert and to increase the cost of hiring a smuggler.

Today, illegal migration to the U.S. is far more deadly and expensive than it was 30 years ago, just as the authors of the 1994 Border Patrol plan anticipated.

But the report’s authors believed that potential migrants would forgo the dangers of migrating to the U.S. without authorization, as well as the high costs of getting there. They thought potential migrants would simply stay in their home countries.

They were wrong.

The strategy of discouraging migrants from coming to the U.S. by making it more difficult required a large federal investment in border enforcement and cooperation from other countries, especially Mexico.

Over the past 30 years, the Border Patrol’s budget has grown more than sevenfold, and the number of agents stationed along the southwest border has quadrupled.

The U.S. government has also built physical infrastructure to stop migrants from entering the country, including massive walls that extend into the Pacific Ocean.

In more remote areas, drones, surveillance towers and extreme temperatures do the work of border control, often with deadly consequences for migrants.

The U.S. also provided more than US$176 million in funding between October 2014 and Sept. 30, 2023, to support Mexico’s immigration control efforts.

There is some evidence that stricter border enforcement deterred Mexicans from crossing illegally into the United States after the 1990s. The number of migrants apprehended by the Border Patrol along the southwest border plummeted from 1.6 million between October 1999 through the end of September 2000, to 327,577 between October 2010 and the end of September 2011.

But the deterrent effect of increased enforcement did not last. Migrant apprehensions at the southwest border began to rise again in 2012 and spiked to 851,508 between October 2018 and Sept. 30, 2019. After falling briefly during the pandemic, total apprehensions averaged 1.9 million per year between October 2020 and Sept. 30, 2024.

These numbers exceed the historic peaks in 1986 and 2000 – despite the much greater costs and dangers of migrating illegally today.

In 2023, my research team and I interviewed over 130 migrants in Colombia, Costa Rica and Mexico to understand why they were taking such enormous risks to get to the United States. What we found is that deterrence isn’t working because of shifts in who is migrating and why they are leaving home.

Until 2011, the vast majority of illegal border crossers were Mexicans, mostly young men seeking higher incomes to support their families. As the Mexican economy recovered and fewer young people entered the labor market, Mexican workers had less need to migrate. Those who made it to the United States stayed put instead of going back and forth.

Today, more than 60% of the migrants who cross the U.S. border without legal authorization are from places other than Mexico, including Central America, Venezuela, Ecuador and Haiti. Forty percent of them are parents traveling with children.

Many of these migrants are fleeing chronic violence, rampant corruption, natural disasters or economic collapse.

For these migrants, it is worth the risk of being kidnapped, dying in the desert or being deported to escape a desperate situation.

“If they deport me, sister, I will come back,” a Honduran mother of three told us in Tijuana in June 2023. “If you go back, you die. So you have to go forward, forward, forward all the time.”

While prevention through deterrence has not stopped migrants, it has enriched smugglers, corrupt government officials and other criminals who take advantage of vulnerable migrants on their way to the U.S. border.

“Before I would charge you $6,000,” explained a Salvadoran smuggler to an Associated Press reporter in December 2019. “Now I am charging you double. And depending on the obstacles on the way, the price can go up.”

This doesn’t include the fee to cross the heavily fortified U.S.-Mexico border, which increased from a few hundred dollars in the 1990s to between $2,000 and $15,000 today.

According to one estimate, smuggling revenues in the Americas grew from $500 million in 2018 to $13 billion in 2022. “Criminals have shifted from their primary business, which was drug trafficking,” the director of an anti-kidnapping unit at an attorney general’s office in Chihuahua, Mexico, told a journalist in June 2024. “Now 60 to 70% of their focus is migrant smuggling.”

It’s not just smuggling that is lucrative. As Mexico’s own immigration policy has become more restrictive, migrants have fallen into the clutches of an extensive extortion racket that involves kidnapping migrants once they set foot in Mexico.

Prevention through deterrence is a failed policy with a tragic human cost. It doesn’t stop migrants who are fleeing dire conditions, and it fuels violence and criminality. Drug cartels, armed groups and corrupt officials get rich while insecurity spreads, fueling more migration. It is a vicious cycle that will likely only get worse with stricter enforcement and mass deportations.

This article is republished from The Conversation, a nonprofit, independent news organization bringing you facts and trustworthy analysis to help you make sense of our complex world. It was written by: Katrina Burgess, Tufts University

Read more:
How Trump might target DACA recipients and other immigrant groups

A century ago, anti-immigrant backlash almost closed America’s doors

Trump promises to deport all undocumented immigrants, resurrecting a 1950s strategy − but it didn’t work then and is less likely to do so now

Katrina Burgess does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.