" It is difficult for the concerns of the Christian faith to be adequately met in one sole political entity; to claim that one party or political coalition responds completely to the demands of faith or of Christian life would give rise to dangerous errors. Christians cannot find one party that fully corresponds to the ethical demands arising from faith and from membership in the Church. Their adherence to a political alliance will never be ideological but always critical; in this way the party and its political platform will be prompted to be ever more conscientious in attaining the true common good, including the spiritual end of the human person"

(Pontifical Council for Justice and Peace (Vatican City): The Compendium of the Social Doctrine of the Church, n. 573).
 

"Parties are a human invention. They're handy because they help people to organize for a political expression but political parties are not God. They are not even divinely instituted organizations. And if the platform of a particular political party would advocate something which is contrary to our beliefs we cannot support that aspect of the party's program and I don't think that candidates who are Catholics can be expected to advocate part of that political program."

"All rights presuppose the right to life. If the right to life is not defended, the defense of all other rights is useless. It becomes a lie, because it would mean that the defense to the right to work, to society, etc. applies only to some, and not to all."

"The Holy Father speaks of the protection of life as the fundamental realization and respect for human rights. Without that realization, without that respect for the right to life, no other discussion of human rights can continue; it must be based upon the foundation of human dignity and the right to life."

"Party loyalty is and must be a secondary value, often very important, but nonetheless, secondary. Political parties have the obligation to defend the common good, and where the political party no longer defends the common good, but rather only ideological interests, then the members of that party are obliged to vote against the party. They are obliged."

"Faithful Christians have a duty to participate in society by voting so that they may advance the common good. The common good is defined as the good of all. 'The good of the majority' is not at all the same thing as 'the good of al.’"

Bishop Elio Sgreccia, Vice-President of the Pontifical Academy for Life, Vatican City

Bulletin Inserts on Faithful Citizenship