Here are some books that had a significant cultural impact [on The Left] during the 60s & 70s you might want to consider ...
btw, All the books you mention, show how much reading I need to do!
Your "Kennedy Years" stuff seems very good, but I am surprised by the inclusion of "Happiness is a Warm Puppy." I cannot believe that there can be much of a connection with Trudeau's Doonsbury. Schutz did his best work in the early 60s [which is difficult to appreciate since Peanuts was very bad during its last decade], but I associate Schulz with being 'slight'; indeed, l think that Dr. Seuss wrote some of his great books in the early 60s and would have been better appreciated by The Creative Forces, in kindergarten and beyond, then and later. ["Red Fish, Blue Fish" "Green Eggs and Ham"]
An important cultural wrapup for the Kennedy period was Schlesinger's A Thousand Days, which everybody bought and read, in mourning for the fallen president.
Re The Johnson Years, I didn't think that the book on which "The Graduate" was based was known before the movie came out, and when read afterward, paled to the film -- but I could be wrong. And I didn't think of Ann Tyler as being important until "The Accidental Tourist" -- but then, I am no fan.
I'm not sure I understand your complaint about "Hair." I think while the musical was in NY it became a nationwide phenomena. The work was about more than just hippies; it was about the war and changes in race relations. I think the phenomena associated with "Hair" helped to inform the country re feelings & idealism of youth at the time. And, in ways that are hard to appreciate today, the songs were courageous and quirky.
An important book I remember about that time was "Everything You Always Wanted to Know About Sex But Were Afraid to Ask." I think this book is important to your story since it widened the door of the sexual revolution. The book itself was full of misinformation [e.g., Coca-cola's value as a contraceptive], but it popularized discussion about things that used to be too personal, such as masturbation, sex practices of children and the elderly, etc. It was Masters & Johnson with a lower Fog Index.
Too, I think Thompson's "Fear and Loathing in Las Vegas" was huge and is worthy of greater mention. The writing is absolutely brilliant; I think that it set a new, literary-quality hilarity standard for The Left that was very influential. [In addition to spuring others to try Gonzo Journalism] Also, just the sudden, enormous influence of Rolling Stone magazine is hard to appreciate today. For a while, Rolling Stone had a monopoly as the spokesvehicle for the cultural Left, much more lively and vital than Ramparts and whatever else was around. I think it also indirectly spawned People Magazine, and Entertainment Today and all the Entertainment reporting industry. Yep, I think RollingStone is TO BLAME!
In about 1970, other books/stuff that was important was "The Smothers Brothers Show" which challenged the establishment with great hilarity. A book popular on high schools "Student as Nigger" was huge. [You can find the opening essay on the Internet; the book included a lot of other weird stuff. I remember a short story in it called (something like) The Crawlspace.] Also, "Looking for Mr. Goodbar" was a big deal.
For poetry, the huge seller was -- gulp -- Rod McKuen, who was a mediocre & sentimental poet. But I think he paved the way for many to read more-substantive work, such as Ferlinghetti [Didin't 'Coney Island of the Mind' come out about then?] and Leonard Cohen, who also released his "Suzanne" Album.
Plus, one mustn't forget Firesign Theatre who had a string of three albums that remain classics of drug-influenced comedy. (Others of their albums were duds.) The puns! The puns! I suppose, though, that Cheech and Chong were more widely known (and far less clever). Of course, all this has to have had some influence on Monty Python, which came along in the middle 70s [The Pythons are sort of like the Beatles of comedy. The Brits adding just the right twist (and shout)]
In non-fiction "Bury My Heart at Wounded Knee" was wept over by The Left, and read countrywide. [But, I confess, I didn't read it.]
Also, there was an important book by Chaim Potok, written during the period, that I am surprized you -- of all people -- left out.
And finally, THE important war book during the period. A MUST for your essay. It was written in 1939. Won the first National Book Award. Banned during WWII. Re-printed in 1959; swept the youth due to the Vietnam War. I hope you can figure it out from that ...