So, are you Celt? Anglo Saxon?
Mostly the latter, though I am a mix of mostly Germanic and Anglo blood, with a little Ukrainian.
Ethnicity is very specific and each race IS 'visibly other'.
No they aren't. 'Visible other' is a relative position, it's the 'odd man out' who has little hope of assimilating because he sticks out like a sore thumb. Now, the Irish COULD be a 'visible other' to the English if the most exotic substantial minority in England were Irish people, but that isn't the the case right now. Toni Morrison had a really good interview with Charlie Rose wherein she discussed the concept and how it has affected American literature; I recommend it to anyone, but it is particularly elucidating on this particular question.
The traditional system only lasted as long as a certain ethnic group was able to fend off invasion or assimilation.
True, that's why ethnic solidarity is so important.
In the US, and most parts of Western Europe, it has been assimilation that has dotted ethnicity and culture. I would think that people such as yourselves would have DNA Haplogroups all in order and be able to weed out those who do not conform to your desired ethnicity.
Oh, in a vacuum, you would be right. But we aren't in a vacuum, not even close. And someone else has already given us an identity, against our protests. We wanted to be Italian Catholics, Pennsylvania Dutch, Irish, Scandinavian, etc., scattered into our respective enclaves. We were perfectly happy with those communities, a few decades ago. But people of my current political persuasion have been being told that we are 'white people', that we hold collective guilt, and have been been cast as public enemy #1 by the far left since we were teenagers, some since they were children. Meanwhile, any space where white people congregate with one another is seen as somehow 'oppressive' (the logic on that one is mind-bending), so the identities we used to have weakened as our old neighborhoods were 'enriched' and those cultural identities broke down. So we've stepped into those shoes that were cobbled for us, just as the English stopped thwopping the Irish over the head the second the Luftwaffe started droning off their shores. A threat, perceived or real, makes smaller differences seem insignificant.
Really, when you melt something down, blend it together, and pour it into a mold, the outcome is pretty predictable.
Political sovereignty is the result of either social contract or domination. So, It sounds to me as though the alt right prefers the latter.
Political sovereignty is always based on dominion. People just like saying 'social contract' because it sounds much more nice than 'do what I say or I'll put a bullet in the nape of your neck'. People like to feel like they have power, especially when they don't, so they tell themselves that they voluntarily gave it all away to someone else before they were born. Most states are an iron fist in a velvet glove.