The US Bishops' Marriage, Unique for a Reason blog ties the question of marriage into their two week fortnight for freedom efforts:

"...The Church’s teaching on marriage and on religious liberty both find their roots in Christian anthropology, that is, the understanding of the human person and his or her dignity. Concerning marriage, upholding the meaning of marriage as the union of one man and one woman upholds human dignity by, among other things, honoring the uniquely complementary natures of man and woman, their capacity for union and fruitfulness, and the child’s birthright of being given the best chance to know and be raised by his own father and mother.

Concerning religious liberty, as was said in a previous post, man’s ability – and responsibility – to seek truth and conform his life to it necessitates religious freedom. In fact, Bl. Pope John Paul II saw religious freedom as so important to human dignity that he called it the “source and synthesis” of rights basic to human flourishing. Concern for the human person means concern for marriage,and for religious liberty."