Paul Ryan’s bishop, Robert C. Morlino, writes that he is “proud” of Paul Ryan, who “is aware of Catholic Social Teaching and is very careful to fashion and form his conclusions in accord with [its] principles.”
He quickly adds, however:
It is the role of bishops and priests to teach principles of our faith, such that those who seek elected offices, if they are Catholics, are to form their consciences according to these principles about particular policy issues.
And so he goes on to teach about voting principles:
the formation of conscience regarding particular policy issues is different depending on how fundamental to the ecology of human nature or the Catholic faith a particular issue is. Some of the most fundamental issues for the formation of a Catholic conscience are as follows: sacredness of human life from conception to natural death, marriage, religious freedom and freedom of conscience, and a right to private property.
Violations of the above involve intrinsic evil — that is, an evil which cannot be justified by any circumstances whatsoever. These evils are examples of direct pollution of the ecology of human nature and can be discerned as such by human reason alone. Thus, all people of good will who wish to follow human reason should deplore any and all violations in the above areas, without exception. The violations would be: abortion, euthanasia and physician-assisted suicide, same-sex marriage, government-coerced secularism, and socialism.