Thanks for posting this brilliant essay by one of my two favorite living historians.
With respect to the hard left, the islamofascists and the Euro-neonazis, it's obvious why they hate us. Beyond these specific groups however, I believe the explanation lies not so much in politics but psychology. In particular, the psychology of adolescents.
There is a quite impressive cadre of such historians and authors. The left never mentions them or their work.
I think that this is exactly right.