The Catholic Church has intervened in political discourses to enact legislative and constitutional provisions establishing marriage as the union of a man and a woman, resisting efforts by civil governments to establish either civil unions or same-sex marriage.
Pope Francis is the first Pope to support same-sex civil unions, saying that "same-sex civil unions are good and helpful to many". While the Catholic Church explicitly denies its blessing for marital union between two people of the same sex, the Catechism of the Catholic Church goes into great detail when describing the legitimacy of individuals who identify as gay as beloved children of God.
Church teaching
On 3 June 2003, the Congregation for the Doctrine of the Faith published "Considerations Regarding Proposals to Give Legal Recognition to Unions Between Homosexual Persons" opposing same-sex marriage. This document made clear that "legal recognition of homosexual unions or placing them on the same level as marriage would mean not only the approval of deviant behaviour... but would also obscure basic values which belong to the common inheritance of humanity."
Catholic legislators were instructed that supporting such recognition would be "gravely immoral", and that they must do all they could to actively oppose it, bearing in mind that "the approval or legalisation of evil is something far different from the toleration of evil". The document said that allowing children to be adopted by people living in homosexual union would actually mean doing violence to them, and stated: "There are absolutely no grounds for considering homosexual unions to be in any way similar or even remotely analogous to God's plan for marriage and family. Marriage is holy, while homosexual acts go against the natural moral law."
In October 2015, bishops attending the Fourteenth Ordinary General Assembly of the Synod of Bishops in Rome agreed on a final document which reiterated that while homosexuals should not be discriminated against unjustly, the Church was clear that same-sex marriage is "not even remotely analogous" to heterosexual marriage. They also argued that local churches should not face pressure to recognise or support legislation that introduces same-sex marriage, nor should international bodies put conditions on financial aid to developing countries to force the introduction of laws that establish same-sex marriage.
North America
Canada
In July 2003, the hierarchy of the Catholic Church in Canada, the country's plurality religion, protested the Chrétien government's plans to include same-sex couples in civil marriage. The church criticisms were accompanied by Vatican claims that Catholic politicians should vote according to their personal beliefs rather than the policy of the government. In late 2004, Frederick Henry, Bishop of Calgary, wrote a pastoral letter saying "Since homosexuality, adultery, prostitution and pornography undermine the foundations of the family, the basis of society, then the State must use its coercive power to proscribe or curtail them in the interests of the common good."
United States
In the United States, the leadership of the Catholic Church has taken an active and financial role in political campaigns across all states regarding same-sex marriage. Human Rights Campaign said that the church spent nearly $2 million in 2012 toward unsuccessful campaigns against gay marriage in four states, as the second-largest donor representing a significant share of the contributions used to fund anti-gay marriage campaigns. A 2012 Pew Research Center poll indicated that Catholics in the United States who generally support gay marriage outnumber those who oppose it at 52 percent to 37 percent.