White House Chief of Staff John Kelly sure doesn’t think very highly of immigrants.

When asked in a Friday morning interview with NPR’s Morning Edition about President Trump’s harsh new “zero tolerance” border policy — one that, among other things, literally takes children from undocumented parents and puts them in the government’s care — Kelly justified it by saying that undocumented people just can’t hack it in America. Here’s the full quote:

The vast majority of the people that move illegally into the United States are not bad people. They’re not criminals. They’re not MS-13 ... but they’re also not people that would easily assimilate into the United States, into our modern society. They’re overwhelmingly rural people. In the countries they come from, fourth-, fifth-, sixth-grade educations are kind of the norm. They don’t speak English; obviously that’s a big thing. ... They don’t integrate well; they don’t have skills. They’re not bad people. They’re coming here for a reason. And I sympathize with the reason. But the laws are the laws. ... The big point is they elected to come illegally into the United States, and this is a technique that no one hopes will be used extensively or for very long.

Some critics were quick to point to the fact that these comments were broad, and arguably racist, generalizations about a group of heavily Latino immigrants. Kelly is asserting they don’t “assimilate,” when the best evidence suggests that undocumented immigrants integrate well and commit crimes at lower rates than native-born Americans.

Others noted that this rhetoric almost exactly echoed the way that Americans in past generations talked about other immigrants, including Italian immigrants like Kelly’s maternal grandfather. Kelly’s ancestor “never spoke a word of English,” Politico’s Ben Strauss reports, “and made his living peddling a fruit cart in East Boston.”

This speaks to a fundamental point about immigration politics in the United States. The best evidence we have suggests that on most quantitative metrics — rate of English-language acquisition, penchant to commit crime, and the like — Latino immigrants are as successful, if not more, than previous waves of immigrants that we’d now mostly describe as “white” (Italian, Irish, etc.).

But there were panics about the ability of those groups to “assimilate” in the past as well, back when they weren’t considered to fall into the same ethnoracial categories as native-born white Anglo-Saxon Protestants. The language of “assimilation” is more often than not code for a kind of cultural panic, a sense that these immigrants don’t “belong here,” rather than well-grounded fears about the damage immigration is doing to American society.

This, again, isn’t speculation: The best research we have suggests that anti-immigration sentiment is rooted less in fears about the effect of immigration on wages, or other similar economic concerns, than about a sense of threat to the dominant group identity.

“Evidence about the role of economic concerns in opposition to immigration ... has been inconsistent,” three University of Michigan scholars write in a review of the literature on the subject. “On the other hand, symbolic attitudes such as group identities turn up as powerful in study after study.”

The bottom line is that we should take John Kelly seriously but not literally. There’s no doubt that he’s an immigration hawk, but it’s hard to defend his position, or the Trump administration’s, on the grounds that he’s offering in this interview. There’s something else going on here, and it’s not hard to guess what it is.