These guys can quote ancient encyclicals and dress up in all the archaic costumes but the Holy Spirit of God has not penetrated a single cell of their stone cold hearts.
Most moral issues are black and white in the abstract, but complicated messes in the concrete. The fallacy here is comparing one issue in abstraction with a host of issues concretely.
FYI if the abortion rate is X, then a policy that could reasonably be expected to lead to X-1 is a proportionate reason to vote for a pro-choice candidate with that policy. "Proportionate reasons" are not as hard to come by as some Catholics would have you believe.