On Free Speech and Nazism

Free speech is commonly cited as being something fundamentally American – very few nations around the world, including other Western strongholds, permit their citizens absolute freedom in this regard. Take, for example, Germany. Present day Germany explicitly prohibits any outward manifestation of Nazi sentiments or affiliations. Nazism and Adolf Hitler left an indelible mark of shame upon the nation, and for that reason, Germany has resolved to purge it from her lands. Are such motions justified?
In brutally murdering nearly 12 million people, Nazi Germany permanently scarred the countless millions who lost loved ones. Germany's prohibition of Nazism may easily be justified as a small measure designed to protect those who have suffered so very much. In the United States, a country renowned for her freedom and equality, racially charged, incendiary groups are protected by the Constitution's First Amendment defense of freedom of speech. Which is correct – Germany in suppressing hate groups, or the United States in protecting them?
In developing an answer to this query, it is first necessary to explore major instances of first amendment right suspension in the United States. President Adams authorized the Alien and Sedition Acts in 1798, and President Wilson successfully sought the passage of the Sedition Act of 1918. In both instances, the federal government sought to limit and make punishable by force of law any speech or press that would threaten morale during times of war. Such limitations are nigh inconceivable to 21st century Americans. In restricting freedom of speech, the federal government is merely empowering itself. In robbing opposition of their voices, the balance of power shifts dramatically away from the people and to the government.
As such, preservation of freedom of speech is imperative, despite the protections afforded to hate groups. Public opinion and derision sufficiently quell the voice of such bodies – the government has no need to do so.