That's actually a very interesting question, but no.
White leftist culture, at least as I define it, isn't as simple as your opinions on taxes, economics, or even being liberal on social/racial issues. As I see it, it defines a specific set of self-hating whites who are either indoctrinated, or project whatever personal issues they have into self-hatred for themselves or left-wing ideology.
Thomas and Carson are two successful African-American men who are "assimilated" into American culture. Liberal or Conservative has nothing to do with it, and neither does "white or black". There is also no such thing as "White conservative culture", because conservatives do not see race, but Americans. There is no such concept as "White conservative or Black conservative" to us, it is alien. We are all Americans first. We do not think about race all day.
Therefore, it isn't possible for Thomas or Carson to assimilate into "white conservative culture" because such a thing does not exist.
Conservatives are not akin to racialist, alt-right reactionaries (who are certainly right-wing racialists), and I don't consider classical liberals to be akin to cultural marxists or racial leftists, which is what white leftist culture falls into.
Refusing to see race enables racism in a society which has historically been racialized and segregated. "Not seeing color" is a cute idea, but the world isn't at the point yet where we can turn a blind eye to past wrongdoings and pretend that they don't affect the present. Your derangement over the teaching of racial issues in schools belies that assertion, anyway.
