I have often wondered this same thing. If one adheres to the teachings of the Catholic Church and lives their lives accordingly, I don’t understand this either. I guess, some people completely separate the Church from government and support representatives that uphold the laws of our land; (which does provide for legalized abortion) I don’t know, I reaching here because it really does not make sense. I’ll be curious to hear others’ views on this, as well.
Looks like we never got one.
Because Republicans, like Democrats, are sinful, morally depraved, small-minded, selfish human beings, and nominal Catholics raised with false teaching tend to stick with them if they don’t feel inspired by outside examples to change. Our lack of charity; our refusal to let the Holy Spirit sanctify us; our hard-hearts, are weapons from Satan that he uses to keep many outside from entering. Our countless sins of omission - accumulating into the billions and trillions and tens of trillions - do injury to billions of souls.
For the second question, it is important to keep in mind that being in a political party does not mean support of all their positions.