I would love the left to explain to me how it is that we keep seeing white people pretending to be non-white improve their socio-economic chances.

In a white-supremacist state, nobody would do that. But we keep seeing it. We don't even need to look at fringe loons like this, examples are on TV screens every day. Kim Kardashian and Ariana Grande, for instance. Two rich and famous white girls who spend their lives casually masquerading as ethnic minorities.