Whites are 56% and blacks 14% of the US total population. Meaning 30% of the country is missing from this book. But, if you adjust for age, it is actually much more misguiding than that, for people under 50 whites are about 40-45%, and black roughly the same share.
The book essentially ignores almost half of the country, and realistically where is should be the most relevant, it misses the mark even more. Whites live far more rurally than any other demographic, and blacks live far more often in the city centre.
The place where you have the most of the race-class issues are the cities, here the upper class is actually quite diverse, as the population is far more hispanic, asian, and black. It also varies a lot by city. Even on its premise the book does not apply.
The CEO of google is an Indian progressive, if he has racist attitudes, it's going to be interlinked with his exposure to the cast system as a bhramin. Or we can look the centre of the stock exchange in the US and international banking, New York. This city is 30-40% Jewish, meaning you cannot get anywhere in the halls of power unless you are an ardent zionist. Bloomberg couldn't even stop the Hasidic community from slaughtering live sin chickens on the open streets and swinging them above their heads.