Nearly 2 million Mexican Americans, more than half US citizens, were deported without due process during the Great Depression, reminiscent of what is unfolding today

One sunny afternoon in February, a large group of plainclothes federal agents descended on Los Angeles’s La Placita Park, a sanctuary and bustling cultural hub for the city’s growing Mexican diaspora. Wielding guns and batons, they barricaded the park and demanded proof of citizenship or legal residency from the congregants trapped within.

Those who failed to produce papers were arrested. More than 400 people were detained and forced on a train back to Mexico, a place many had never been.

It’s a scene many fear will come to pass in president-elect Donald Trump’s second term, especially after he doubled down on a campaign promise to “launch the largest deportation operation” in US history, and confirmed he would use the military to execute hardline immigration policies.

But this particular episode happened in 1931, as part of an earlier era of mass deportations that scholars say is reminiscent of what is unfolding today.

The La Placita sweep became the first public immigration raid in Los Angeles, and one of the largest in a wave of “repatriation drives” that rolled across the country during the Great Depression. Mexican farm workers, indiscriminately deemed “illegal aliens”, became scapegoats for job shortages and shrinking public benefits. President Herbert Hoover’s provocative slogan, “American jobs for real Americans”, kicked off a spate of local legislation banning employment of anyone of Mexican descent. Police descended on workplaces, parks, hospitals and social clubs, arresting and dumping people across the border in trains and buses.

Nearly 2 million Mexican Americans, more than half US citizens, were deported without due process. Families were torn apart, and many children never again saw their deported parents.

Hoover’s Mexican repatriation program is, among mass deportation efforts in the past, most similar to Trump’s stated plans, said Kevin R Johnson, a professor of public interest law and Chicana/o studies at the University of California, Davis, School of Law.

“This was a kind of ethnic cleansing, an effort to remove Mexicans from parts of the country,” Johnson said. “This episode had a ripple effect that lasted generations, and a long-term impact on the sense of identity on persons of Mexican ancestry.”

In Los Angeles, Johnson said, it was a common practice for Mexicans to deny their Mexican ancestry and claim Spanish or European heritage to avoid suspicion. Well into the 1960s, Johnson said, people were afraid to leave home without a passport or identification papers lest they be arrested. More than 400,000 Mexican Americans were deported in California alone, but the legacy of repatriation went unacknowledged for many decades. Finally, in 2005, California state senator Joseph Dunn helped pass legislation apologizing to people who suffered under the program.

Since his first presidential run, Trump has invoked President Dwight D Eisenhower’s mass deportation program as a blueprint for his own agenda. During the second world war, the US and Mexican government enacted the Bracero program that allowed Mexican farm hands to temporarily work in the US. But many growers continued to hire undocumented immigrants because it was cheaper. In 1954, the Eisenhower administration cracked down on undocumented labor by launching “Operation Wetback”, a yearlong series of raids named after a racial epithet for people who illegally crossed the Rio Grande.

Border patrol agents used military-style tactics to sweep up laborers from farms and factories and send them back to Mexico. More than 3,000 people were expelled every day, and many died under inhumane conditions in detention and transport. The government said it deported more than 1 million people in total, though historians have put the actual number at closer to 300,000.

The politics of deportation have always contained an important “racial dimension”, said Mae Ngai, a historian whose book Impossible Subjects explores how illegal migration became the central issue in US immigration policy.

Trump has deployed racist tropes against various ethnic groups, including Mexicans as drug-dealing “rapists” and Haitians as pet eaters, while lamenting a lack of transplants from “nice”, white-majority countries like Denmark and Switzerland. Last month, sources close to the president told NBC News that he could prioritize deporting undocumented Chinese nationals.

“He’s been very clear about going after people of color, people from ‘shithole countries,’” she said, referring to a 2018 remark from Trump about crisis-stricken nations like El Salvador and Haiti.

Trump could plausibly deport a million people using military-style raids of the Eisenhower-era, Ngai said, but it is unlikely that he can expel 11 million undocumented immigrants. (According to an estimate by the American Immigration Council, deporting 1 million people a year would cost more than $960bn over a decade.) Still, Ngai said, his rhetoric alone could foment fear and panic in immigrant communities.

But Eisenhower’s immigration approach also differed from Trump’s in notable ways, Ngai said. Though the administration did launch flashy raids, it also allowed farm owners to rehire some deportees through the Bracero program, essentially creating a pathway for authorized entry into the US. So far, Ngai said, Trump has hammered down on deportations without providing an option for legal immigration or naturalization. “He doesn’t know the whole story of ‘Operation Wetback’,” she said.

Deportations also appear to have harmed the local economy. Far from protecting jobs for white Americans, the repatriation of Mexicans “may have further increased unemployment and depressed wages” in the 1930s, according to a 2017 academic paper from the National Bureau of Economic Research. Economists today predict a similar outcome: expelling millions of undocumented construction, hospitality and agriculture workers could shrink the GDP by $1.7tn, according to a study by the American Immigration Council.

Johnson said there’s little evidence to suggest that the mass deportation efforts of the 1930s and 1950s were successful at curbing illegal immigration. The number of undocumented immigrants has tripled since the 1990s, he said, despite a steady rise in border security measures and patrol agents. “It’s a mistake to think building a wall or engaging in nasty deportation campaigns will end undocumented immigration,” Johnson said. “As long as people can obtain work legally or illegally, they’re going to keep coming.”

But fearmongering may be the true legacy and intention of mass deportations campaigns, Johnson said. Self-deportation has been the policy preference for establishment Republicans, he said, including former presidential candidate Mitt Romney. “Part of the strategy,” Johnson said, “is making the lives of undocumented immigrants so unpleasant that some will just leave, and discourage others from coming”.