Why does the left hate free speech? Because they don't know how to talk about the substantive merits when they are challenged. Having submerged themselves in disciplining each other by denouncing any heretics in their midst, they find themselves overwhelmed and outnumbered in America, where there is vibrant debate about all sorts of things they don't know how to begin to talk about. They resort to stomping their feet and shouting "shut up"... when they aren't prissily imploring everyone to be "civil."