Ironically my own HS curriculum had us both read The Adventures of Tom Sawyer and watch Gone With the Wind precisely because of their racist content (that is, as a way of understanding and critiquing racism in everyday culture).

I can totally understand bringing TKAM down a few notches in the canon, and bringing some of the many, many neglected works by authors of color to the fore. But even the thought of outright banning from the curriculum would have been seen as quite regressive indeed, at the time.

It's ironic to think "how far" we've come since then.

If Mario Savio were to show up in Sproul Plaza in 2020 (as opposed to 1964), it would most certainly be under the banner of conservatism. What we now know is that the Left isn't interested in free speech per se, but rather free speech for people who agree with them.