The Roman Catholic leadership does not support the GOP. I would say that the RC leadership is very critical of the GOP on several issues.
As far as abortion goes, Pope Francis has called it an "absolute evil", a "horrendous crime", and the "murder of an innocent person". And Gaudium et Spes called it an "unspeakable crime" (you don't dissent from Vatican II, do you?).
But yes, a number of Catholics voted for Trump over Hillary because, as caustic as he was, we saw him as preferable to Hillary. Was abortion an issue? Yes. So wasn't Benghazi, her use of her private email server for national security matters, the sexual harassment of multiple women by her husband (why didn't she speak up?), her dullness as a candidate, her support from the rich elites.