There are many Catholic priests who think that there is no principled theological objection to the ordination of women. I'm not going to express a view on these boards as to whether or not I agree with them. But clearly they don't think od themselves that they're heretics!
It's a dogma; See Ordinatio Sacerdotalis, penned by HH John Paul II, making it blackletter and reiterating and dogmatizing what HH Paul VI said to the Anglican Communion when the Anglicans decided to ordain women: women are invalid subjects for priestly ordination. HH Paul immediately closed the dialogues towards mutual recognition. That also lead to the eventual formation of the Anglican Use within the Roman Church. HH JP II's Ordinatio Sacerdotalis uses the "settling the question once and for all" wording...
Link to OS in case you care to read it - I linked to the English, rather than the Latin or Italian:
Ordinatio Sacerdotalis (May 22, 1994) | John Paul II
The thing is, most Catholics in the US don't know the catechism. Most have never actually read the official catechism, let alone the assorted doctrinal statements made ex-cathedra.
And note, the issue was in discussion in the 2nd century, too... and the 16th, 19th and 20th centuries...
If doing Alt-History, the place to make the change would be St Paul's ordination of St Pheobe. If he had ordained her to the presbyterate, the whole of Catholic History would be different. He did use the Greek "diakonos" for her, and she was trusted by him to teach from his letters.
We also know that, in the second century church, the deaconesses were communed in the same manner as the deacons, unlike the subdeacons, and actually had authority over the subdeacons. St Paul, such a rabble-rouser...
