> He just wanted to talk about how the particular loudmouth brand of annoying leftist came to prominence.

Nah, this is just not true about that essay. This is sort of excessive "lets twist what people say with maximum leftist spin so that we can paint everyone who disagree with them as crazy". It is getting repetitive, tiresome and amounts to a massive amount of online gaslighting. Center and left are all supposed to pretend that everyone is leftist just concerned with some extremists, no matter how much it is clear it is not the case, unless someone actually supports nazi party ... and sometimes even longer.

That essay did not even cared about actual history of events either.