On Monday, Iowa Rep. Steve King made headlines for perhaps the worst possible reason: He approvingly retweeted a British neo-Nazi, Mark Collett — a man who has, among other things, claimed the porn industry is a secret Jewish plot to destroy Christian families. It’s been more than a day now and King has neither deleted his tweet nor apologized for signal-boosting an anti-Semite:

Europe is waking up...Will America...in time? https://t.co/GqZ3E1lCyh — Steve King (@SteveKingIA) June 12, 2018

This is nothing all that new from King, who once asserted on national television that no “subgroup of people” has contributed more to the world than white Europeans. Given his long history of spouting white supremacist rhetoric, it makes sense that he would be comfortable playing footsie with the likes of Collett.

But what’s particularly interesting here is the subject of their agreement, what Europe is allegedly “waking up” on: immigration. It’s the issue that brings together the Trump wing of the GOP, of which King is an extreme member, and the European far right, which at this point has become a powerful electoral force in countries as diverse as Hungary, Italy, and Austria.

The basic idea is that Europe and the United States are facing a “civilizational” threat, meaning mass immigration of people from non-European backgrounds. This, they believe, is the principal long-term threat to the survival of the “West” as a civilization — and hence needs to be curtailed. It isn’t always explicitly racist, but it comes pretty damn close.

Politicians across the Atlantic recognize their fellow travelers in this crusade. That’s how you get King praising Hungarian Prime Minister Viktor Orbán — perhaps the leading opponent of letting refugees into Europe, who literally built a fence separating Hungary from other European countries to block refugees from crossing the border:

Diversity is not our strength. Hungarian Prime Minister Victor Orban, “Mixing cultures will not lead to a higher quality of life but a lower one.” https://t.co/ZlMXzcc87w — Steve King (@SteveKingIA) December 8, 2017

European politicians have been acutely aware of the dangers of rhetoric about cultural and racial superiority for most of the post-World War II era, for the somewhat obvious reason that sounding like Hitler was electoral poison. But more recently, you’ve heard some politicians get more comfortable with rhetoric that breaks this taboo.

Just on Tuesday, for example, Austrian Chancellor Sebastian Kurz called for a German-Italian-Austrian “axis” to fight “illegal migration.” You’d think the fact that those countries were members of the literal Axis during World War II would cause him to shy away from that particular word, but Kurz, a fairly clever politician, used it anyway.

What you’re seeing, with this rise of far-right anti-immigration politics across the West, is a destruction of gatekeeping norms: People’s hostility toward immigration is giving politicians license to mainstream more extreme voices and challenge longstanding anti-racist taboos. What’s worse is that a significant number of voters across the Atlantic seem to like it.