Many of the boomers where also influenced in a sneaky way by the communists of the Frankfurt School. Herbert Marcus was a communist critic who wrote One Dimensional Man -- a popular book back then -- and made the statement "Make LOVE not war" which became a popular hippie slogan. The Communists influenced in both a direct and indirect way the hippie generation to rebel, especially against the establishment and the Vietnam war. Again, the Frankfurt School came to America to escape the Nazis but also was the viper in the heart of her bosom. Believe it or not the USSR also played a part in shaping liberal (hippie) thought -- normally people wouldn't think of it, but its true. Liberation theology back then (being a hippie), as now (with Wright), is very close to Marxism.
The sad thing is that the student protesters who couldn't bring down the establishment back then became profs and that is why the university is left leaning today. That is why Bill Ayers, Ward Churchill and many postmodern thinkers are there.