Black representation is one thing, but it’s almost a red herring. You can make Harvard 10-12% Black without changing the demographics too much.[1] The bigger question for Asians I think is competition with elite whites. A “proportional representation” type system handicaps Asians against whites, for no comprehensible reason. Harvard is 13% Asian, but Caltech is 40%. Why should white students be insulated from that competition?

[1] In my opinion there is no similar justification for preferences in favor of Hispanics. Studies show that Hispanics are similarly situated to previous generations of white immigrants: https://academic.oup.com/qje/article/135/2/711/5687353. Their income disparity is explained by recency and character of immigration, and disappears over time. You see the same phenomenon about Asian groups that comprise primarily refugees. Vietnamese people were as poor as Black people in the 1970s. Today their household income is slightly higher than white people. By contrast, Black and indigenous people face persistent disparities that are not disappearing over time.