On June 2, Mr. Lübcke was fatally shot in the head on his front porch, in what appears to be Germany’s first far-right political assassination since the Nazi era. The suspect — who made a detailed confession last week, only to retract it this week under a new legal team — has a violent neo-Nazi past and police record, renewing criticism that Germany’s security apparatus, with its long track record of neglecting far-right extremism, is still failing to take the threat seriously enough.

Far-right militancy is resurgent in Germany, in ways that are new and very old, horrifying a country that prides itself on dealing honestly with its murderous past. Raw and hateful language has become increasingly common online, and politicians are increasingly under threat, with some now requiring protection.

“The murder of Walter Lübcke shocked me like it shocked a lot of people,” the country’s foreign minister, Heiko Maas, said on public television last week, while calling for Germans to hold weekly protests against far-right extremism.

“I asked myself — what is happening in our country?” he said. “If you look at how much hatred and harassment there is on the internet — a lot of it directed at local politicians, bureaucrats, sport and cultural clubs — then I think we need to stand up and say that this is unacceptable.”