Ben Zimmer is the language columnist for the Wall Street Journal.

Back when he was just a New York real estate developer, Donald Trump often complained about pernicious “infestations” that would bring down his property values. In a 1992 interview, Trump told Charlie Rose about the area of Manhattan where he hoped to build the Riverside South complex: “We’re looking to get zoning for a piece of land that’s unzoned, that’s employing no people, that’s sitting there rotting. It’s rat-infested.”

Three years later, after Trump became a co-owner of the Empire State Building, he tried to oust the building’s management company, run by his nemeses Leona and Harry Helmsley, by filing a lawsuit in which he claimed that the Empire State had become nothing more than a “tarnished, second-rate, rodent-infested commercial building.”


And in 2010, annoyed at delays in bringing an enormous banquet facility called “Trump on the Ocean” to Jones Beach State Park, Trump griped that the only thing visitors could see was “a rat-infested dump.” (Hurricane Sandy finally scuttled Trump’s beachfront boondoggle two years later.)

As president, Trump is still fixated on infestations, but now he wields that language against those he sees as political foes, especially people of color. He tweeted Saturday that the majority-black Baltimore district of Rep. Elijah Cummings is a “disgusting, rat and rodent infested mess” where “no human being would want to live.” That followed his notorious tweet of July 14, in which he told four progressive congresswomen of color to “go back” to “the totally broken and crime infested places from which they came.”

Trump’s defenders are saying he was referring to rodents and crime, not people. But the history of how “infestation” has been used politically shows that the distinction is blurrier than they would like to admit. Historically, the verb “infest” has been used to talk not just about literal pests and diseases, but also to compare people—very often minorities and immigrant groups—to pests and diseases.

The word “infest” goes back to a Latin root, “infestare,” meaning “to attack or trouble,” and from early on in English it could relate to groups of people seen as a hostile, invasive force. One chronicle from 1602 cited by the Oxford English Dictionary speaks of how early England was “infested” by plundering Saxons and Danes.

Over time, “infestation” became primarily associated with pestilent animals or pathogens that could do harm to humans by overrunning them in large numbers. But the idea that people from stigmatized groups could be the ones doing the infesting would become a potent trope in anti-immigration rhetoric in the United States and elsewhere.

Chris Wallace confronted Trump’s acting chief of staff, Mick Mulvaney, on “Fox News Sunday” about the president’s rhetoric. “‘Infested.’ It sounds like vermin,” Wallace said. “And these are all six members of Congress who are people of color.” Mulvaney countered that Wallace was “spending way too much time reading between the lines.” The Fox host responded: “I’m not reading between the lines. I’m reading the lines.”

As CNN host Victor Blackwell pointed out in an emotional response to the jabs at Cummings, “Donald Trump has tweeted more than 43,000 times. He’s insulted thousands of people, many different types of people. But when he tweets about infestation, it’s about black and brown people.”

Trump’s targets in the past have included Rep. John Lewis, whose Atlanta district he called “crime infested,” and who he said should focus on “the burning and crime infested inner-cities of the U.S.” Trump has claimed that Democrats want “illegal immigrants, no matter how bad they may be, to pour into and infest our Country.” He has said that sanctuary cities involve “this ridiculous, crime infested & breeding concept,” and that “we have an ‘infestation’ of MS-13 GANGS in certain parts of our country.” And back in the Obama era, he questioned why soldiers were being sent into “Ebola infested areas of Africa.”

Trump’s rhetorical choice is far from benign, New York Times columnist Charles M. Blow notes, because “infestations justify exterminations.” Rolling Stone senior writer Jamil Smith made a similar point last year after Trump lashed out at MS-13 gang members: “When Trump speaks of immigrants ‘infesting’ America, he speaks in the language of genocide, not governance. By likening people to insects or vermin, even if he considers them criminals, he provides himself license to be an exterminator. We know that story.”

In his 2018 book Contagion and the National Body, Gerald O’Brien, a professor of social work at Southern Illinois University Edwardsville, surveyed the history of U.S. immigration debates for illustrations of the “organism metaphor,” which draws parallels between the human body and the body politic. O’Brien found that “groups that are targeted for control are often compared to parasites or ‘low animals’ capable of infection and contamination.”

The author of a 1921 anti-immigration tract called The Sieve, for instance, wrote that enclaves such as “‘Little Italy,’ ‘Little Ghetto,’ ‘Little Hungary,’ or any other ‘little’ colony in New York or Kalamazoo” were “parasites on the oak of national prosperity, and should be eradicated.”

O’Brien’s research draws on metaphor theory, as pioneered by George Lakoff and Mark Johnson in their 1980 book Metaphors We Live By. When people in marginalized groups are likened to vermin or parasites, O’Brien argues that the metaphor can be reinforced by the idea that such people live in vermin-infested environments. In other words, when Trump describes Cummings’ constituents as living in a “rat and rodent infested mess,” he is reinforcing the metaphor that the people belong in the same conceptual category as the vermin.

As Andreas Musolff explored in Metaphor, Nation and the Holocaust: The Concept of the Body Politic, it was just this type of infestation metaphor that propelled Nazi ideology against the Jews, who in the party’s propaganda were constantly analogized to parasites, tapeworms, termites and the like. O’Brien finds similar rhetoric in American anti-Semitic literature, such as the 1934 book Are These Things So?, published by the World Alliance Against Jewish Aggressiveness, billing itself as a “Study in Modern Termites of the Homo Sapiens Type.”

The book included a news clipping about a termite infestation in Greenwich Village, making the metaphorical relationship explicit: Eastern European Jews were “infesting” New York City just as real termites were. Louis Farrakhan revived the metaphor when he tweeted last year, quoting one of his speeches, “I’m not an anti-Semite, I’m anti-termite,” which led to him being kicked off Twitter.

Trump may be unaware of this rhetorical history, but that does not make it less disturbing that his language has been overrun by such a troubling turn of phrase.