The issue with the way Germany handles Nazism is that their constitutional right to freedom of speech doesn’t match ours. The Basic Law states that there is freedom of speech, but in another article it expands on the details by forbidding political speech that glorifies either the Nazi regime or other movements considered to be a threat to human rights.
That interpretation isn’t really compatible with the first amendment in the United States. As long your speech isn’t directing political violence as it occurs, you’re free to speak out freely on any subject for any cause. After all, we have both Nazi groups and communist organizations in the United States.
Neo-Confederates can march freely here. Neo-Nazis cannot march freely in Germany. The US Constitution and the German Basic Law are completely different documents with two different ideas on what constitutes free speech.
Mainly because both documents are framed from two different sources. The constitution is based on political, social, and economic liberty. The Basic Law is at its core focused on the protection of human rights.