I disagree with your read of that blog post.

In fact, in various parts of the text, DHH is actually trying to distinguish between a "simple" view that it's a "far right" political agenda, and instead the fact that people feel loss of identity, and lack of security.

I don't know enough about DHH to state for sure that he is, or he is not, a right wing or fascist supporter, but in my view that blog post isn't proof of that. I've read it and found it to be an attempt at reframing the problem with a fresh view.

Yeah, to solve lack of identity, he blames non natives. It's not a reading, you can find it on every history book

Incorrect. He doesn't blame non-natives. He blames native politicians for allowing incompatible (sic!) non natives in, in way too large numbers. He tells about the problem, the cause of it, and describes how there has been an increased awareness of the problem in many countries and how the political winds changed.