The official document, Lumen Gentium of Vatican II unambiguously makes clear the role of the laity in the temporal world. This is one paragraph that is so clear and so straight forward that a first grader could read it and understand it once they understood the word "temporal."
Mission Field of the Laity
Lumen Gentium emphasized that the distinct call of the laity is in the secular world, where they do the work of the Church by the way they live out their everyday lives:
"It is the special vocation of the laity to seek the kingdom of God by engaging in temporal affairs and directing them according to God's will. They live in the world, in each and every one of the world's occupations and callings and in the ordinary circumstances of social and family life—. There they are called by God to contribute to the sanctification of the world from within, like leaven, in the spirit of the Gospel, by fulfilling their own particular duties." Vatican II
Now, having read this, I would suggest that Rick Santorum knows what his role as a layperson is to "seek the kingdom of God by engaging in the temporal affairs and directing them according to God's will." Rick Santorum is a Vatican II lay Catholic and although the world might think him to be "crazy" we've always known that being a Catholic in the public square is not about being successful (getting elected) BUT being faithful! What a powerful witness Rick Santorum is to what Vatican II actually called Catholic politicians to be! Thank you Senator Santorum!
Please note Bob Schieffer's astounding but typical bias!:
Now compare Rick Santorum's Vatican II faith to the "faith" of Nancy Pelosi who knows nothing or believes not in what Vatican II taught her as a lay Catholic to "seek the kingdom of God by engaging in the temporal affairs and directing them according to God's Will"! What a scandal to post Vatican II Catholics Nancy Pelosi is; will she repent? For the sake of her immortal soul, pray that she does!