One of the charges that conservatives constantly hurl at liberals is that they are basically hypocrites. Although they say that hearing all points of view is the cornerstone of free democratic societies, they really only want to hear that with which they already agree.
Take the case of the highly inflammatory provocateur Milo Yiannopoulos. Recently, Yiannopoulos’s right to speak at UC Berkeley was hotly contested by Berkeley students. It even sparked outside agitators to engage in violence. Does this mean that Berkeley students were thereby violating one of the core principles of liberal thought? Yes, if they wanted to prevent Yiannopoulos from speaking altogether. No, if they were merely expressing their right to protest hate speech.
Conservatives confuse the basic principle that all points of view, however odious, have a fundamental right to be heard with the dubious principle that every point of view is entitled to be heard without any protest whatsoever. As if conservatives don’t protest loudly when they hear speakers with whom they disagree strongly.
Just because I condemn hate talk before or after the fact is not equivalent to preventing it in the first place, unless of course it can be shown that there is a very strong possibility it will lead to bodily harm. Tolerance of intolerance does not mean that I don’t have a fundamental right, yea obligation, to speak out forcefully against intolerant points of view.
Because liberals endorse the right of all viewpoints to be heard does not mean that it categorically endorses all viewpoints. An open mind is not the same as a head full of holes.
The heart of liberalism is healthy debate, not the uncritical acceptance of any point of view.