On Thursday’s Tucker Carlson Tonight, the political commentator focused on one of the issues threatening to shut down the government: immigration. One of his guests ended up arguing that children of Hispanic heritage born in the United States are not American.

Author, columnist, and “actual thinker” (in Carlson’s words) Mark Steyn conceded that immigration could have economic benefits, but that they are outweighed by the “cultural transformation” America is undergoing as a result. One example of this so-called transformation, Steyn said, is that “the majority of grade-school children in Arizona now are Hispanic.”

“That means, in effect, the border has moved north,” Steyn, who is Canadian, said.

.@MarkSteynOnline on DACA: "In Arizona, a majority of the grade school children now are Hispanic. That means Arizona's future is as a Hispanic society. That means in effect, the border has moved north." #Tucker pic.twitter.com/tCJsNMlT0u — Fox News (@FoxNews) January 19, 2018

Carlson called this “bewildering” for “people who grew up here.” (Although perhaps not for the Hispanic children, or generations of Hispanic Americans, who also grew up here.)

The most recent data shows Hispanic children actually make up 43 percent of Arizona students. It’s true that Hispanic students outnumber whites in the state. But that includes many American citizens and others who have grown up in the US.

The “border has moved north” only if you equate being American with being white — a racist theory that’s become ever more prominent in the immigration debate. As Vox’s Jane Coaston wrote, this view “holds that whiteness is more valuable to participation in the American experiment than anything else — even a deep and abiding belief in American ideals.”

So it might not be surprising that Carlson has become a hero to white supremacists, as Carlos Maza explained earlier this year: