I agree with HMS that a big difference between today and past eras is that “the left” actually has some real influence, and the right is flipping out about it.
In the 60s, fuzzy headed hippies were getting beaten up in the streets, and civil rights activists were being killed by cops. But (to Jackmanii’s point), hippies and civil rights activists weren’t brawling with their opponents in the House chamber, because none of them were getting elected to the House.
If we define “the left” as European-style social democrats, even ten years ago Bernie Sanders was a unicorn. Now progressives have real influence within one of the major parties. As usual, the threat of actual progress evokes extreme reaction from the privileged classes.