Ban Nazism in America?

The riot in Toledo, Ohio resulting from a couple dozen Neo Nazi Party whites marching in a predominantly black neighborhood raises again immense political and cultural issues . The attacks upon police after the Nazi's had departed were allegedly perpetrated by black gang members drawn to the demonstration like moths to flame. With the target of their anger gone, why did the black gangs vent their rage at police? Are police seen as an extension of the mindset of the Neo Nazi Party? Should they be?

One 80-year-old resident reportedly said they should never have allowed the Nazi's to march there. Should our Constitution's protection of civil liberties extend to protect a terrorist organization whose history is replete with genocide, torture, and hate? And if the U.S. were to outlaw displays or demonstrations of Nazi activism, what organization or group would follow to be added to the banned list? More fundamentally, are American civil liberties described in the Bill of Rights, absolute? Or, without sacrificing the protections afforded by the Bill of Rights, is it possible to make exceptions for groups whose core organizing principles could lead to civil war or insurrection if left unchecked?

Racism in America is alive and well. Afterall, racism is born out of perceptions. Non-acceptance and disrespect for differing races in America by members of other races, is readily evident daily in the banter on the internet revolving around such topics. Can laws ever alter those perceptions? Or, given America's racially contentious past, has America achieved the best mix of absolute civil liberty protections for groups like Nazi's while maintaining public and political cultures which condemn the organizing principles of such division oriented hate groups?