I can't speak for all Roman Catholics, but as I am one, I suppose I can give my impressions here.
As we all know, even though it's against their own best interests, those of Judaic derivation in America tend to vote Democrat, for the rabid anti-Semite party and its candidates.
A great deal of this is due to the secularization, the "mainstreaming," of that group--or rather, its attempts to assimilate into greater American society. They want to be considered Americans, not Jews; never mind that most of us always considered them 100% Americans anyway.
They want to be part of the Establishment, and the Establishment is Democrat and liberal.
Well, there one has it for the Jews.
As we all know, even though it's against their own best interests, Roman Catholics in America tend to vote Democrat, for the rabid anti-God party and its candidates.
I suppose to some degree what I've said about the Jews also applies to the Catholics in the northeastern states and urban areas outside of that.
They want to be with the "in" party, the "in" people, which in their case are corrupt Democrats.
(This does not hold true outside the northeastern states and large urban areas, where Catholics never felt an inferiority complex--and of course outside the northeastern states and big cities, we Catholics tend to be very red.)
All my life, I've been seeing a shift from the Democrats to the Republicans with every election, but damn it, it shifts at the pace of a stalled glacier, like maybe .01% each election. It's always been shifting in my own lifetime, but one needs a damned microscope to see it.