A belief in free speech means absolutely nothing unless you exercise it to defend those with whom you violently disagree. Any moderate citizen can, without too great a strain, tolerate somebody at the other end of the democratic spectrum. The true test of such commitment comes when the reasonable person (of course, almost all of us think ourselves reasonable) runs up against a genuine spittle-flecked loon arguing for some school of totalitarianism. You find him or her dangerous? What they are saying offends your inner core? Big deal.