There is indeed a leftist form of radicalism in the US. Twitter mobs and cancel culture might be compared to Trumpian trolling, although I doubt they're exactly the same. Bernie's supporters are much more focused on concrete policies, and progressives are likely better educated than the Trumpians. So if you tested their relevant knowledge and critical thinking skills, I suspect the progressives would come out on top. Even if progressives are naive in certain respects, they make up a more authentic coalition, seeking rational fixes for real political problems (campaign finance reform, ending the filibuster, universal health care, higher taxes on the wealthy, etc).
Even the inflammatory rhetoric on Twitter is part of a concrete agenda which has real-world consequences (canceling offenders' careers). This has become totalitarian, and it's based on flimsy postmodern reasoning (as I explore in other articles), but I don't know if that's the same as pure trolling or empty symbolic protest. Currently, the right-wing extremism seems much more hollow than the left-wing kind.
By the way, I have my doubts about that talk of a political spectrum with equal "wings":
