America's founding principle was a pile of Dutch, English, and Germans casting aside their ancestral loyalties and working together to build something new, based on values, ideals, and mutual respect. Over time, this expanded steadily to include anyone of any race or religion.
For more than half of the USA's existence, Catholics were maligned for their subversive influence, and after that Germans, Japanese, Eastern Europeans, Chinese, and later Arabs were treated with suspicion. Nonetheless, the USA persisted with the logic that background shouldn't matter, even those coming over and making good lives for themselves at the same exact time that their homelands waged war against America.
No other nation has this. It would be considered suicidally forgiving. 100 years ago the WASPs ran the show, but now have resoundingly faded away into the background. No other ruling class would be so willingly supplanted, because almost every other society has its flag planted and defined by those ethnic and religious markers.
These '''''rebels''''' are so coddled they don't realise how generous America has been to so many. Most countries are just vehicles to advance the cause of its nation, its dominant ethnic group. And that nation existed long before the country (Ireland, Finland, Russia, Poland, France, China, Thailand, Ethiopia, Oman, etc) and will probably survive that country's future collapse. Some of those I listed had been conquered and subjugated plenty, but it was because the nations had a sense of self beyond the state that made those identities so robust.
Ethnic cleansing still happens today because nations feel threatened, and find if a minority group gets too big they may usurp the infrastructure out of said nation's hands. Look at Lebanon, or almost any sub-saharan african country. The nations within that state are always fighting over who controls the whole thing.
But for America? the country and the nation are one and the same. You cannot have a USA grounded in communist ideology, or monarchism, or fascism because then what is an American without those core founding principles? The term becomes meaningless-- and that's actually probably where you get these open borders fanatics from. They don't appreciate the US' ideological glue, so figure demography is nothing more than a cudgel with which to procure power.
Maybe you can argue white and black Americans who's ancestors settled before 1776 have no other stake by now, but there cannot be an American as we know it today without the USA as a country. This is why these revolutionaries are retarded and dangerous, because if they chip away at the foundations hard enough without having a cast-iron replacement which is as impossibly accomodating as the USA is (read: certainly not anarcho-communism) then the whole make-believe game implodes. This is what you're seeing with the rise of id-pol. Without the flag to rally around, Americans rally around their tribal status, but because America traditionally discouraged this, the tribes become warped; as a Latino, or a White, or a Black... none of which are viable identity markers in Africa or Latin America or Europe, but are as good as its gonna get in post-collapse America, certainly better than identifying first as a Feminist or a Sexual Minority.
TL;DR Antifa/BLM are retarded because they're condemning America for racism when its one of the few countries in history to at least TRY to leave tribal affiliation at the door for mutual benefit. The pseudo-intellectuals think they can use id-pol like a tool to further their agenda, thinking everybody else is too stupid not to think of it first, when in actuality, it's like a fish hammering at cracked glass on the tank, believing if the tank is smashed it can reform the shards into a more fashionable wall in the split seconds before all the water rushes out.