Catholic progressives often criticize “creeping infallibility” and discount the authority of Church’s ordinary magisterium when it comes to sexual morality. Galileo is often cited. This approach has been used for other purposes.
Pius XI repeatedly condemned Nazi and Fascist racism, culminating in the encyclical Mit Brennender Sorge.
The Italian fascist official Robert Farinacci went to the Nuremberg rally in 1938.
Emma Fattorini in Hitler, Mussolini, and the Vatican, writes that
Farinacci on that occasion countered the pope’s attack on the recent fascist racial manifesto by invoking the pope’s non-infallibility regarding scientific and terrestrial topics; just as the Church had erred in the case of Galileo, so it was mistaken regarding racial theory.
The German Jesuit eugenicist Hermann Muckermann took a similar approach when Pius XI condemned eugenics in Casti Connubii. Muckermann thought that the pope had no competence in scientific matters, and the Vatican would eventually realize that eugenics was scientific and valid.
My point: it is dangerous to dismiss constant Church teachings when one is influenced by contemporary attitudes that, in retrospect, are deeply pernicious. The incidents cited above should be a caution to those who dismiss every non-infallible teaching as essentially having no authority.