That was very interesting post, although I cannot concur, because it is done without a realistic historical context, and done without regard to geopolitical reality.
As to the former, in the end, every society has a mythos, the text, and a subtext, which is what we do not want to talk about, like my partial Indian ancestors fate.
It is of course true that the dominant settler class was WASP, which is ethnicity of the American the power elite.
It is now a rapidly degrading elite, which is the real American problem.
In the end, Mexico is not the United States; we decided that in 1846, when we did not annex Mexico, as a significant part of the WASP Southern planter class wanted.
If you want a civil war, just pretend that those verdicts as to the text/victors and subtext/vanquished did not happen: nothing personal, except for as usual, all the dead bodies of Realpolitik.
Canada is the proof; look at the wound that is Quebec in terms of national unity, always on edge of coming apart as a country, because they tolerated two national identities. This is why Russia uses force against Chechens and Chana against Tibetans, because in the real world it is an imperfect world in terms of who rules and who is ruled over. The alternative is national disunion, which means outside power intervention.
This is what Russian strategist Igor Panarin wants for the U.S., which would be good for Russian and proabably Chinese power, but not for anyone else, because when you say the United States has done bad things, it must be asked in the context of compared to who and to what alternatives.

Excellent post -
peece,
dj

My comment makes absolute sense. Outside powers have always wnated to dismember the United States along regional and ethnic lines.