Take a look at research by Caroline Hoxby and Christopher Avery. The vast majority of low-income high achievers do not apply to any selective college. More outreach, better guidance would help but the majority of the Ivy League caliber “one-offs” are white while 15% are Asians and 15% are URMs.

Legacy admissions play a role but it is more of a factor in which rich white students are admitted - primary legacy admit rates are 40% at Harvard, 33% at Princeton, 23% at Yale - than in the overall percentage of white students in the undergraduate student body. At Yale, only 15% of students come from families in the…