I'm no Heidegger aficionado, but I liked this summary of a book I've looked at: “Heidegger: The Introduction of Nazism into Philosophy.”
"[The author] traced the connections between the völkisch themes in both Heidegger and Nazi ideology and the shared conviction that only a return to a presumably earlier and more authentic existence can save us from the spiritual wasteland wrought by modernity."
Stated that succinctly, it reminds me of Rousseau.
The worship of the primitive,
as a more authentic existence,
is a march toward disaster.
When civilization is "no way to live",
and savagery meets small resistance,
death comes so much faster.
(via Stephen Hicks)