For the first time in recent history low tiered whites will have an even lower tier to look down upon.
In the history of the United States there were always other whites for whites to look down upon.
English looked down on Germans, Germans looked down on Italians, Italians looked down on Irish, Irish looked down on Polish...at some point they all became status. So while they've always managed to use social economic status, that is dynamic, that can change.
These South Africans, particularly aren't wealthy, they are highly educated or highly skilled. So these trailer park, rural, section 8 white folk are going to have other white folks to literally point their fingers at that have a funny accent and suck at life.
They may initially embrace the but it will be an eye opening experience. Our Americans are "white" those guys just have white skin.
There won't be enough for them to affect school districts or change a community, like when you look at large segments of Muslims, or Indians (Asian), Asians, Africans (Sudan, Nigerian, etc)