I'm nor sure you stated a case at all. I've probably misread this but your argument is basically thanks to white supremacists the world has an opposite reaction and great change and movements were born. It's like saying because we had wars we had cultural upheaval and that's a great thing. It sure is but it hardly defends wars or supremacy.
I loved the history lesson but your case for white supremacists is weak. As white supremacy stands today, antisemitic, racist, homophobic and islamophobic, you could say it has evolved into something different than it's original purpose. And no supremacist is calling themselves supremacists. They're just the dominant culture. If you argued that white supremacy is a social construct created by the disenfranchised than you would have a better case.