Here is what Pope Benedict told the Catholic Bishops of Minnesota (which has a marriage protection amendment on the ballot this November, as we know) during their recent visit:
... In this talk I would like to discuss another serious issue which you raised with me during my Pastoral Visit to America, namely, the contemporary crisis of marriage and the family, and, more generally, of the Christian vision of human sexuality. It is in fact increasingly evident that a weakened appreciation of the indissolubility of the marriage covenant, and the widespread rejection of a responsible, mature sexual ethic grounded in the practice of chastity, have led to grave societal problems bearing an immense human and economic cost.
Yet, as Blessed John Paul II observed, the future of humanity passes by way of the family. Indeed, “the good that the Church and society as a whole expect from marriage and from the family founded on marriage is so great as to call for full pastoral commitment to this particular area. Marriage and the family are institutions that must be promoted and defended from every possible misrepresentation of their true nature, since whatever is injurious to them is injurious to society itself”.
In this regard, particular mention must be made of the powerful political and cultural currents seeking to alter the legal definition of marriage. The Church’s conscientious effort to resist this pressure calls for a reasoned defense of marriage as a natural institution consisting of a specific communion of persons, essentially rooted in the complementarity of the sexes and oriented to procreation. Sexual differences cannot be dismissed as irrelevant to the definition of marriage. Defending the institution of marriage as a social reality is ultimately a question of justice, since it entails safeguarding the good of the entire human community and the rights of parents and children alike... -- L'Osservatore Romano