I think we are mixing up two things here, which are the freedom of speech (which is absolute) and the way it can be exercised, (which is not). We all have the right to make love or to defecate. We do not have the right to do this at times or places which cause enormous offence to other people.
I did not read many supporters writing here in support of the Protestant thugs, who wanted to march through Catholic areas of Northern Ireland, hurling abuse (and often worse) at the residents. The object was not to exercise freedom of speech (as they claimed) but to cause injury and offence. How are these Nazi thugs any different?
I know of no constitution anywhere, which wishes to take away my right to fart. If, however, I choose to exercise it loudly in a place of worship, I can expect someone to remove me or to tell me to do it elsewhere.
American Nazis have the right to express their opinions and to walk the streets of their states. They do not necessarily have the right to do both at the same time.