As the U.S. Capitol insurrection, the prevalence of the QAnon conspiracy, and widely believed claims of election fraud indicate, potentially tens of millions of Americans are outside the consensus on the most fundamental U.S. democratic values: faith in official election results and the peaceful transfer of power. As a German, I am frightfully reminded of the Weimar Republic, which resulted in the end of Germany’s first democracy and the rise of domestic extremism from within. Modern Germany is built on the legacy of the failure of its first democratic experiment and the unspeakable global suffering and destruction that followed. This legacy has been deeply ingrained in post-World War II Germany’s philosophy of “militant democracy”—the idea that toxic and poisonous ideologies can spread within a population to sow distrust and anger against the political order and its most fundamental values. The success of German democracy today indicates Germany’s ability to overcome its previous failure and offers lessons for the United States as well as other countries seeking to counter extreme ideologies.