Rep. Steve King, R-Iowa, has gained notoriety for his often contentious – and, occasionally, almost overtly racist – comments about immigration and the demographics of the United States. On Sunday, in a tweet about the nationalist Dutch politician Geert Wilders, King again appears to have crossed the line.

“Wilders understands that culture and demographics are our destiny,” King wrote. “We can’t restore our civilization with somebody else’s babies.”

The formulation of “our” civilization being at risk from “somebody else’s babies” is a deliberate suggestion that American civilization is threatened by unnamed “others” – almost certainly a reference to non-Westerners. The idea that national identity and racial identity overlap entirely is the crux of white nationalism; King’s formulation above toes close to that line, if it doesn’t cross. American culture, of course, was formed over the past two centuries by the assimilation of immigrants from a broad range of nations – first mostly European but later a broader diaspora. Iowa, the state King represents, remains one of the most homogeneously white in the United States.

King’s tweet echoes comments he made during the 2016 presidential election when, as a supporter of Donald Trump, he suggested that white people had contributed more to civilization than any other “subgroup.”

That happened during a panel discussion on MSNBC hosted by Chris Hayes, in which King took issue with Esquire’s Charlie Pierce for suggesting that the Republican National Convention was energized mostly by “loud, unhappy, dissatisfied white people.”

“This ‘old white people’ business does get a little tired, Charlie. I’d ask you to go back through history and figure out,” King said, “where are these contributions that have been made by these other categories of people that you’re talking about, where did any other subgroup of people contribute more to civilization?”

“Than white people?” Hayes responded in astonishment.

“Than, than Western civilization itself,” King replied. “It’s rooted in Western Europe, Eastern Europe and the United States of America and every place where the footprint of Christianity settled the world. That’s all of Western civilization.”

Wilders is a deeply controversial politician in Europe, thanks to his views on race and culture. Last month, for example, he referred to some immigrants from Morocco as “scum,” while pledging to “make the Netherlands ours again.” His Freedom Party has made significant gains in polling in the Netherlands over the past few years. King’s tweet on Sunday was not the first time he has praised Wilders for the latter’s opposition to immigration. Shortly before the 2016 election, King tweeted, “Cultural suicide by demographic transformation must end,” including Wilders’s Twitter handle.

Even before the advent of Trump, King railed against the criminal threat posed by immigrants from Mexico. He gained national notoriety in 2013 for saying that, for every immigrant in the country illegally who becomes valedictorian, there are “another 100 out there that – they weigh 130 pounds, and they’ve got calves the size of cantaloupes because they’re hauling 75 pounds of marijuana across the desert.”

Just as Wilders was the beneficiary of praise from King, King received praise of his own for his “our civilization” tweet. Quoting King’s comment, former KKK grand wizard David Duke tweeted an enthusiastic “GOD BLESS STEVE KING!!!”

Last summer, King was criticized for having a Confederate flag on his office desk – especially odd since Iowa was a Union state in the Civil War.