The question is how many Catholics are actual liberals
Quite a few apparently worldwide at least
Where I grew up they were in general more socially liberal than say Pentecostals or Missionary Baptist were ....much more
Catholics have tended to vote democrat until very recently
That may be an urban perspective more than religious historically
And lately a racial perspective as in US Hispanics
Ironically I think the Catholic Church in Africa is the most doctrinaire
Looks like a copy has gotten a bit pricey since I picked one up back in the '80s