Well, I am white and think that there is a difference in the way people socialize depending on their socioeconomic status, the area they grew up in, and the culture/language they are exposed to at home. And in the US it’s basically all white people who are most advantaged in these aspects. It will likely change over time as more Hispanic/Asian people become second+ generation immigrants rather than first, though

I remember going to college not so long ago and meeting kids who had grown up in the US who still had an accent/manner of speaking that they got from their parents (like a Chinese or Spanish accent). And of course there are very smart kids who grow up with AAVE or strong regional accents, some of whom are probably white but who probably aren’t from a good socioeconomic class.

Because the Senate is over 90% white, and most of the rest are at least half-white.

To people in this country, that's what leadership looks like, so if you grade based on leadership, that's what you're going to get. Not playing identity politics here, just stating a fact.