I reviewed a book a couple of years ago that was briefly available for sale on Amazon. It contained pretty much every anti-semitic argument against trans people that you discuss here, going so far as to assert that a cabal of Jews in Davos fund gender clinics as part of a quest to control the world and destroy western values.

The book was sold by a publisher that mostly reprints books from the Nazi and fascist era – apologia for Hitler and Mussolini, 20th century British academic fascists, etc. Although Amazon stopped selling the book after enough people complained (mostly because it calls for death to Jews, I believe), it's still available in hardcover directly from the publisher.

And it gets talked up a lot and reviewed/summarized in alt-right circles that aren't always so fringe.

It's sickening to see these ideas spreading.