In Thier Native Land

I saw this comment in regards to Brexit:

let alone Jamelle Bouie's argument at Slate that Brexit was about "embattled whiteness." While concerns about out-of-control migration did play a major role in the push for Brexit, much of that concern (as Reihan Salam explains, also on Slate) was driven by a massive influx of migrants from Eastern Europe, who are neither black nor brown.

For the sake of argument, lets assume all the immigrants WERE black or brown. How is it OK for whites to be "embattled" in their own native land? Would such an analysis such as "embattled blackness" be acceptable? Is black general opposition to gentrification "embattled blackness"?