Fix has hit the issue nicely. We do not have to rely in the laity, the Church has given us quite a bit of guidance. In addition to the document Fix notes, there is a guide written by then Caridnal Ratzinger and approved by Pope John Paul II:
vatican.va/roman_curia/congregations/cfaith/documents/rc_con_cfaith_doc_20021124_politica_en.html
The whole thing is well worth reading. But two things to consider:
The citation is to the Second Vatican Council. Which gives a fairly extensive explanation of the correct understanding of the human person. This would not seem to permit the concept of accepting policies which, say, oppress and exploit the poor in exchange for a proper policy on abortion.
This idea, that faith should be viewed and respected as a coherent whole is also reiterated in the Doctrinal Note, specifically in the context of limiting harm from secular laws:
(emphasis added)
Notice it is “contents”, plural. The document follows by giving examples of “fundemental and inalienable ethical demands” which “do not admit” exception. The list is more extensive than the laity group’s guide, and includes issues like education, religious freedom, socially just economic growth, protection of minors, and peace.