Chief Justice Huges has written....

"It is only through free debate and free exchange of ideas the government remains responsive to the will of the people and peaceful changes affected.  The right to speak freely and to promote diversity of ideas and programs is therefore one of the chief distinctions that sets us apart from totalitarian regimes.  accordingly, a function of free speech under our system of government is to invite dispute.  It may indeed best serve it's high purpose when it induces a condition of unrest, grace to satisfaction with conditions as they are, and even stirs people to anger.  Speech is often provocative and challenging.  It may strike at prejudices and preconceptions and have profound unsettling effects as a presence for acceptance of an idea.  That is why freedom of speech, though not absolute, is nevertheless protected against censorship or punishment, unless shown likely to produce a clear and present danger of serious substantive evil that rises far above public inconvenience, annoyance or unrest.  There is no room under a Constitution for more restrictive view.  For the alternative would lead to standardization of ideas, either by legislatures, courts, or dominant political or community groups."