Incomplete brain dump.
What does it mean to be "progressive"?
Ignore for the moment that a certain slice of the political spectrum tries to co-opt the term "progressive" for its own purposes. The term "progressive" generally means "favoring or advocating progress, change, improvement, or reform, as opposed to wishing to maintain things as they are, especially in political matters."1 Thus the term "progressive" can apply to virtually any political or activist movement, as the point of activism is to change and improve (in the activist's eyes) society by changing law, policy, public opinion or culture.
The socialist progressive seeks a society in which all are subject to equality of outcome. Thus the socialist progressive seeks laws that redistribute wealth. The socialist progressive also seems laws and policies that ultimately reduce the number of people (to facilitate dividing limited resources equally), thus the socialist progressive supports abortion on demand, free contraception, the diminution of marriage in society (to reduce the rate and success of procreation) and the elevation of nonprocreative interpersonal relationships (hence promotion and legalization of same-sex marriage).
The Catholic progressive seeks to shape society according to the teachings of the Roman Catholic Church. Thus the Catholic progressive promotes prohibitions on abortion, rejects the promotion of contraception, rebuffs efforts to normalize same-sex marriage, but also supports the development and execution of government welfare programs in the name of social justice.