As an ethnic white Catholic Democrat, I can confidently (and pretty sadly) say that we are a dying breed.
I disagree with you. If we are going off of our personal experiences, which it sounds like we are, the contrary is true for me. I attend a Catholic parish in an upper middle class area and a very Catholic area that is a perfect descriptor of the "Catholic who now has money and votes Republican" political stereotype. I would say that the parish is split pretty evenly in fact, with a large faction of deeply-religious, "bleeding heart" types that vote Democrat because of their faith rather than in spite of it.
While I don't deny what you are describing in your parish is real, this trend has been very well documented for a long time and is also occurring in Protestantism.
In short, the problem is that conservative Christians produce conservative Christians, while liberal Christians produce liberals who sleep in on Sunday.
