From the article:
"“Our liberty and our happiness depend upon the maintenance of a public culture in which freedom and civility coexist—where people can disagree robustly, even fiercely, yet treat each other as human beings—and, indeed, as fellow citizens—not mortal enemies,” the statement continued.
It cited former slave and abolitionist Frederick Douglass, who said “Liberty is meaningless where the right to utter one’s thoughts and opinions has ceased to exist.”
“Truly open discourse—the debates, exchange of ideas, and arguments on which the health and flourishing of a democratic republic crucially depend—is increasingly rare,” the statement continued. “Ideologues demonize opponents to block debates on important issues and to silence people with whom they disagree.”
The result of hate speech laws, to me, seems to be an increasing echo chamber effect, where people generally gather in communities (virtual as well as physical) in which viewpoints tend to overlap.