The colleges were teaching from the left during the 1960s, it is one reason that left wing students were so supported, promoted, and magnified by the schools.
I think another, more overlooked factor was the "space age" / beat-the-Soviets education movement that came just before the era of the hippie. Stateside propagandists of the "space age" believed the best way to beat the Soviets was to retool their behaviorist advertising methods to incorporate the glorification of science and mathematics in the halls of education, while they remained steadfast disbelievers in classical republican virtues in keeping with their ideological godfather Edward Bernays. So in a very real sense, American and Soviet education shared parallel undercurrents -- a belief that real freedom of the human personality didn't exist or didn't matter, and that economics was basically everything. Naturally, decadence finds a home on such a playing field.
You can watch old film reels -- for example, documentaries about superhighways and suspension bridges -- that convey in thundering masculine voices an overblown optimism that science and mathematics can serve as the bedrocks of society. Yet nowadays, nobody with a strong sense of gritty realism believes that those things have much to say about our civilizational crisis.
There is a gigantic, ambitious, self-willed monster at the heart of the enlightenment glorification of the self, its will, and its "rights", even in America, that few people can bear to look in the eye. We need to look that beast in the eye.