I think that this could go both ways Tec.
An opportunity to even old scores without reprisal? All too common.
Selco mentioned when it occurred around him, there are numerous records of it happening in every war.
Certain groups, already bonded by something such as religion, education, employment, will stay together, others may envy them and you can fill in the blanks.
I don’t see the SD Indians or BLM types joining forces with whitey regardless of common enemy.