For instance, India’s Aryans eventually got gobbled up via interracial marriage with the Dravidians. The Old South had the poorest Whites mating with Blacks, and of course, scandals like the case of Strom Thurmond, where the rich segregationist hypocrite fucks the maid.
Anyway, White Nationalists have a point in wanting to separate totally from non-Whites because Whites being around non-Whites will eventually soften the Whites. It might a total softening – at least not at first, but trust me, the rusting will be underway that will eventually collapse the building.
The US now has many biracial kids now. This a product of integration – it’s simply what happens when two or more races live in the same area.