Trump said Democrats would take away your hamburgers. He’s the one who might.

• Ted Genoways

On Aug. 22, hours before Vice President Kamala Harris took the stage in Chicago at the Democratic National Convention, Donald Trump was claiming that she would abolish Immigration and Customs Enforcement and allow more than 100 million people to cross into the United States. “If Comrade Harris has the chance,” Mr. Trump warned from Cochise County, Ariz., on the U.S.-Mexico border, “our country will be overrun, and essentially it won’t be a country. It will be not governable.” He then renewed his promise to use the military and other government resources to arrest and banish millions of immigrants living in the United States, including those in various humanitarian programs. “With your vote,” Mr. Trump said, “we will seal the border, stop the invasion and launch the largest deportation effort in American history.”

It would be easy to dismiss these threats as posturing to stir up his base, but recent reporting suggests that Mr. Trump’s allies are drawing up plans for the most regressive immigrant policy since 1954, when Dwight Eisenhower’s administration rounded up as many as 1.3 million people, mostly Mexican and Mexican American workers, as part of the openly racist campaign known as Operation Wetback. According to reporting by The Times and The Wall Street Journal, Mr. Trump’s plans — which he describes as “following the Eisenhower model” — would not just remove people already in the United States but also cut off the flow of new migrants. If carried out abruptly and thoroughly, as Mr. Trump has promised, such policies would threaten vital areas of the American economy dependent on immigrant labor. Nowhere is that more evident than in the meat industry.

Not so long ago, America’s meatpackers relied heavily on undocumented immigrants from Mexico and other Latin American countries to staff their factories. But a brutal set of government raids in 2006 changed their calculus. On Dec. 12 of that year, ICE, newly created by President George W. Bush, simultaneously entered six Swift & Company meatpacking plants and arrested 1,300 undocumented workers on charges of immigration violations and identity theft. In the tiny town of Cactus, Texas, agents barred the plant doors and began handcuffing workers. “There were people hiding behind machinery, in boxes, even in the carcasses,” an employee later told The Washington Post.

In Cactus alone, nearly 300 employees, about 10 percent of the town’s population, were arrested. When agents ran out of handcuffs, they tied workers with rope. It was the largest workplace immigration raid in American history. At the time, the ICE director, Julie Meyers, said, “The action should send a clear message to employers: Hiring illegal workers is not acceptable.”

The raids appeared to have their intended effect, and meatpackers soon began seeking out a new class of vulnerable foreign workers: refugees here legally, as well as immigrants who either walked across the border and are allowed to stay for humanitarian reasons or are seeking asylum. Today, nearly half of the people who slaughter, butcher and package beef, pork and poultry in America were born elsewhere. In some packing houses, more than four dozen languages are spoken. In some, Somali, Sudanese and Burmese refugees alone account for as much as a third of the work force. The fact is, America’s largest meat producers are dependent on the immigrants Mr. Trump is threatening to round up and deport.

If he is elected and makes good on his promise to bar refugees, those producers could lose a vital source of labor overnight. If he succeeds in rescinding certain protections for asylum seekers and speeds the process of deportation trials, the entire industry could be brought to a halt. Meat processors are only just recovering from the ravages of the pandemic. This would push them to the breaking point — and perhaps crash the whole food system.

In the nearly two decades since 2006, many of the small towns where meatpacking companies built their processing plants have been transformed. Communities that were once very white are now majority-minority. Nowhere is this more evident than in Cactus, where the former Swift plant is now owned by JBS.

Perched on the wind-scoured, pancake-flat high plains of the Texas Panhandle, Cactus has never been much to look at. The country music legend Waylon Jennings described the town as “nothing but a wide place in the road.” In the early 1970s, the county encompassing Cactus recruited American Beef Packers to build a plant right on the highway. Swift acquired the plant in 1975 and sank millions of dollars into expanding and modernizing the facility enough to butcher 10,000 cattle a week.

For locals, a plant that was supposed to provide more than 900 factory jobs seemed like a godsend. At the time, Gov. Dolph Briscoe made Swift’s president an honorary Texan and went to Cactus to raise the Swift flag. “Texas is on the verge of the greatest development we ever had,” the governor predicted. Instead, Swift depressed wages by hiring so-called boat people from Vietnam, and beginning in the mid-1980s, those workers were largely replaced by an even less protected labor force — undocumented immigrants who were in part fleeing the drug wars in Mexico and Guatemala.

After the raids in 2006, the company needed to replenish its work force fast. Swift executives set up a war room where they posted maps on the walls and circled target cities for recruitment. The company’s H.R. team advertised on the radio and in local newspapers. They bought space on billboards. They sent representatives to job fairs and set up a recruitment station at unemployment offices. But few workers would bite. Finally, Swift started offering free bus service to Cactus from Amarillo. Somali refugees began to apply, and in 2007, after JBS acquired Swift, it stepped up the hiring of refugees to maintain production.

Meatpackers have claimed that they can’t find enough American workers to fill all of these jobs, which are thankless and brutal. Democrats and labor activists view that argument with some suspicion; perhaps if they paid workers more, they wouldn’t have such trouble finding employees. But for now, immigrants are the backbone of the industry. Tyson, one of the world’s largest processors of beef, pork and poultry, estimates that 40 percent of its factory work force turns over each year, and it relies on immigrants to fill many of those roles; 35 percent of its work force — some 42,000 people — are foreign-born. “We would like to employ another 42,000 if we could find them,” a Tyson H.R. executive told Bloomberg recently.

Kim Cordova, the president of the United Food and Commercial Workers International Union Local 7, which represents JBS employees at its flagship plant in Greeley, Colo., estimates that 80 percent of the plant’s employees are foreign-born, working under a variety of official statuses: refugee, temporary, asylum seeker and work visa. And even those here legally could get mistakenly swept up if Mr. Trump makes good on his plans. In 2006, Ms. Cordova recalled: “The government came in, separated families, put them on buses. They were dropped off at different detention centers, without notice. Kids were left at schools with no parents to pick them up.” This is the scene that Mr. Trump is hoping to repeat.

It should be acknowledged: Mr. Trump’s plan for deporting as many as 20 million immigrants would be difficult, if not impossible. (In an April interview, Mr. Trump asserted that the undocumented population was “probably 15 million” and would be as high as 20 million by 2025.) It would require coordination among local, state and federal authorities, including the military, and the participation of hundreds, perhaps thousands, of attorneys. Carrying out a single day of coordinated raids, as ICE did in 2006, is one thing. Reaching the numbers of arrests and deportations Mr. Trump has promised in speeches would require carrying out more than 10 such raids per day for the entirety of a four-year term.

This may be unthinkable, but Stephen Miller, a mastermind of the Trump administration’s immigration policies who would most likely serve in a senior role in a second administration, told The New York Times that ICE would focus on carrying out workplace raids and other sweeps of public spaces as a way of creating a nationwide dragnet. To increase the number of agents to carry out these raids, Mr. Miller said, officers from other federal law enforcement agencies would be temporarily reassigned, and state National Guard troops and local police officers would be deputized. To speed up the process of rejecting asylum claims and deporting immigrants snared by such raids, Mr. Miller described constructing “vast holding facilities” on open land along the Texas border, where the administration would employ “the right kinds of attorneys” to prosecute deportation cases.

The G.O.P. platform also promises that “Republicans will restore every border policy of the Trump administration” and “will use all resources needed to stop the Invasion — including moving thousands of troops currently stationed overseas to our own southern border.” The platform vows to “reinstate ‘remain in Mexico,’” to “bring back the travel ban,” to “end chain migration” and to “use extreme vetting to ensure that jihadists and jihadist sympathizers are not admitted.” Such crackdowns — forcing migrants to stay in Mexico while awaiting asylum hearings, blocking the entrance of immigrants from Somalia and Sudan, preventing immigrants from bringing family members to join them — would spell disaster for big meatpackers.

Deporting a crucial segment of the country’s meatpacking work force and cutting off the supply of replacement workers wouldn’t simply drastically reduce production; it would halt processing at every stage, from feedlots to the packinghouse floor. This would break the supply chain for Big Macs and Whoppers, for bacon and lunchmeat, for Fourth of July hot dogs and Thanksgiving turkeys.

During the early stages of the pandemic, we got a glimpse of what happens during periods of even brief closings of packing houses: the destruction of livestock when there is no place for them to go, lost wages for workers and sales income for farmers, shortages in grocery stores and skyrocketing meat prices for consumers and devastating ripple effects for small towns already struggling to survive.

Ms. Cordova warned that carrying out Mr. Trump’s proposed immigration policies would shut down factories like the JBS plant in Cactus. And without the town’s virtually sole employer, Cactus would turn into a ghost town.

“If Trump’s policies go through, the industry will die,” Ms. Cordova said. “Frankly, nobody in this country wants to do that work.”

For Americans to continue to eat meat, we must break ourselves of Trump’s diet of hate.