That was tried in South Africa and it failed. It failed because because the blacks that were became convinced that the whites were appropriating prosperity earned on the sweat of the black man’s brow. The communist ANC pushed that perception until they were able to get one man one vote across the country and no more of those “awful and racist black homelands”.
Now, what was once a prosperous oasis on the poorest continent on Earth is being turned into just another sub-saharan sewer. Per capita spending on education and healthcare for the blacks in South Africa has declined drastically on a real and and adjusted for inflation basis in the last 25 years, while crime and security spending, not to mention “general governmental expenditures” have skyrocketed. Look at the exchange rate for the Rand vs. the dollar over the last 10 years and it tells an interesting and tragic story.
It failed because there was never true separation. Separate independent countries each with their own sovereignty.
I understand that that would not be an easy thing for us to pull off, but the alternative is much worse (all out race war) which at the end would lead to the same result - separation.
The afrikaners are trying again...
https://en.m.wikipedia.org/wiki/Orania,_Northern_Cape