The pope may not have been, but several german priests such as Herman Muckermann certainly gave german Catholics a way to support eugenics and race theories.
>In 1933, he left his post at the Kaiser Wilhelm Institute, as he opposed Nazi biological racism and the belief that the Nordic race was superior (Dietrich, 1992).[4]
[1] https://academic.oup.com/jah/article-abstract/103/2/498/1750...
[2] https://en.wikipedia.org/wiki/Eugenics_in_the_United_States
[3] https://en.wikipedia.org/wiki/Sterilization_law_in_the_Unite...
[4] https://eugenicsarchive.ca/discover/tree/5233675d5c2ec500000...