I read somewhere that nationally over 50% of Catholics vote consistently Democrat, and those that vote Republican are in the low 30%. Among older (as you say elderly Catholics), that number is upward of 80% who vote Democrat.
I had a dinner table conversation with my aunt and uncle (she Irish immigrant daughter and Catholic, he Italian immigrant son and Catholic).
I put very basic social questions before them, such as "Well, how do you feel about homosexual marriage and partial birth abortion?"
They were appalled I would even ask them these things, and told me how terrible each were. When I said the Democrats were the champions of both, they got very, very, very, very angry with me.
There is no reasoning with people who don't want to discuss truth and logic - especially if your opponent doesn't have the facts on his or her side.
I've tried to go over every one of those social issues with my parents, but it's impossible to keep them focused. They don't want to think about it. FDR and JFK are forever their heroes. You're right, there is no reasoning with them. Again politics is an emotional issue for Dems. Reason and logic don't enter into it.