My sophomore English teacher was over 70 and should have retired a decade before I encountered her. And, as to the college faculty, this was 1963 and the faculty was quite a mixed bag politically -- probably mostly '50s moderate liberals, but at least a few were 'pubbies -- but this was back when most professors still tried to keep their politics out of the classroom: the one who liked the paper best, as a paper, also told me he was concerned I was taking too cynical a view.
The broader point is that teachers should not impose their own political or religious agenda on their students, whether it be a leftist agaenda or a conservative agenda.
Would you extend this to private schools?