Even more: according to statistical studies, out of many socioeconomic variables, being Catholic had the strongest positive correlation with _not_ voting for the Nazis [1].
[1]: https://www.google.com/url?sa=t&source=web&rct=j&url=https:/...
The Vatican was gifted to Church by… fascists.
Is that doing something?
There is ample evidence that you can find with some obvious Googling, but I think this image is a good visual summary:
https://www.gettyimages.es/detail/fotografía-de-noticias/gen...
This is how the Catholic Church treated Franco (not sporadically, but as a custom, you can find plenty of images like that): under a canopy, like they do with images of Saints or the Virgin.
I think in the face of that, anyone will agree that encyclic was not worth the paper it was written on.
Coming back to the encyclic, I think it did have an impact, judging by the measurable refusal of Nazism in Catholic counties as mentioned in my previous comment. The Catholic Church had strong moral authority, and this kind of condemnation was rare: the Red Cross for instance did not raise any [2].
[1]: https://dialnet.unirioja.es/servlet/articulo?codigo=5263342 [2]: https://www.icrc.org/en/doc/resources/documents/misc/6ayg86....
Edit: grammar.
You can start your education here, I know of it because its my country, but I'm sure its only the tip of the iceberg.
https://en.wikipedia.org/wiki/Catholic_clergy_involvement_wi...
Even in democratical societies leaders tend to want to please the church so their brainwashes masses vote for them.