The author has a full length treatment of this subject here, The Myth of American Meritocracy, http://www.theamericanconservative.com/articles/the-myth-of-american-meritocracy/.
It is actually somewhat impressive that the NYT published Ron Unz on this topic because his article in The American Conservative is devastating to much that the NYT holds dear. But the NYT version is not even half the story. The American Conservative piece is a Mac-Daddy presentation on historical trends by racial and ethnic group at the elite colleges measured against the composition of the elite applicant pool.
The author concludes that there is without question a quota to limit Asian-Americans, just as there was to limit Jewish admission in the 1920’s and 30’s, when Jews were overrepresented in the elite applicant pool, just as Asian-Americans are today. Interestingly, Jews are no longer over-reprepresented in the applicant pool, but are admitted at high rates. As a result, they are over-represented now at the elite schools, about 400% of parity at some schools. Since this is a zero sum game, and they are doing affirmative action, something has to give. Asians and non-Jewish whites get the short end of the stick, to an astonishing degree. Whites get it even worse than Asian Americans, as shown by this figure: http://www.theamericanconservative.com/wp-content/uploads/2012/11/eliteenrollment-large.jpg
Ivy League schools have never been strict meritocracies. Plenty of sub-par students have always been admitted due to oligarchic connections, athletics, etc.
I’d guess Jews had have been over-admitted more recently because they tend to financially support their alma maters, and then their children become ‘legacies’.
I’d also bet that Ivy League schools do in fact now have quotas for Jews, but that indicting data just hasn’t caught up. And, given the rate of intermarriage, ‘Jewishness’ isn’t as easy to determine as it once was.