Is there even any argument?
The interview above, subsequent to the tweet before, is supposed to raise questions about whether Rep. King is a racist or just says racist things. The New York Times calls it "an apparent endorsement of white nationalism," because it's not about race, because it's never about race. Besides, it's so indecent to call a white man who isn't from the South or a member of a militia group a racist. It's just not the done thing.
Slate says you have to examine Mr. King's words closely to realize he's a racist. No, you don't.
Steve King is a racist. Period. End of discussion.
His words, which aren't really new at all (the Times gets that right; King does have "a history of making inflammatory statements viewed by many as insensitive or outright racist." Well, some people say, anyway....), are clearly racist. How else can they be interpreted? He says in the interview it's not about "blood," which is nice, because the rest of the world gave up on royalty in the blood ages ago, good to know he's up to date. But to shift to "culture" away from "blood" is not to shift anything at all. It's the shift of Richard Dawkins, who used to wonder in public why Nobel Prize winners in the sciences never came from African and most Asian countries. Culture, donchaknow? That's all Dawkins meant; the superiority of culture.
Or kulchur, as Pound identified it. King and Dawkins wouldn't know the difference. Culture is just the more accepted in polite circles term for "blood" in conversations about "civilization" and what endangers it (hint! People like Steve King and Richard Dawkins!). The terms are synonyms, not subtle but distinct differences.
You don't need a weatherman to know which way the wind blows, and you don't need a Baedeker to know the lay of the land in Steve King's mind. He may aver he isn't being racist in his pronouncements, but that's merely to say he wants to pass in polite society as someone who knows which knife to use at table. Plenty of well-bred racists, too, however. And Steve King isn't all that particularly well-bred.
But he is a racist. Period. End of discussion.