Only Malcom X is missing.
To me, in addition to the stylistic differences, the thing that nails it is the references employed by the book’s author. They all relate to things that were relevant to people at least 10-12 years older than Obama - such as Ayers. I actually remember hearing leftist friends in the 1960s and 70s say they wished they were black, because blacks were the “vanguard of the Revolution.”
But even the black power stuff in the books was, by the time of Obama, a little passe and the left had moved on to other things, such as radical feminism and anti-Israel activities.
I grew up in NYC and am about the same age as Ayers, lived near Columbia and heard the SDS rhetoric, and saw it in the school I attended as well (CCNY - prior to open admissions!). Everything in that book is typical of a person of that generation and milieu, and a younger person from a different background would not have written about those things or even cited those particular authors (popular at that time but found only in a few flaky Communist bookstores 15 years later).
They obviously met at Columbia, Ayers found the black persona he had always wanted and Obama found yet another “mentor” who would sculpt the amorphous, sociopathic personality he possesses.
Only Malcom X is missing.
That has been my theory since last fall. More accurately, they met in New York during the period they both lived there, between 1982 and 1985. Either they met when Obama was at Columbia and Ayers was at Bank Street College of Education (1982-1983), or they met when Ayers was at Columbia and Obama was working locally in New York (1984-1985). They were never enrolled at Columbia at the same time.
My guess is it was the earlier period, as Obama wrote in one of his books of visiting some socialist club in New York when he was at Columbia. It might also explain why Obama went to Chicago, as some have theorized Ayers father is who sponsored Obama in Chicago.