This is not an issue of sacramental marriage. Non sacramental marriages are called natural marriages. Natural marriage has a procreative purpose. When we talk about Sacramental marriage, we are only acknowledging that Christ elevated natural marriage to that of a sacrament. He gives us graces to help us live out our matrimonial vow to grow in holiness. It becomes our vocation of service that helps us on our road to Heaven. Sacramental marriage is not granted to people by the Church. It is simply the reality that when two baptized individuals validly marry, their marriage takes on a sacramental natural. These individuals do not have to be Catholic. They simply have to be validly baptized individuals. If one person is not baptized, it is not sacramental until the non-baptized member is baptized.
When it comes to couples who are Catholic who marry outside of the Church, their marriages simply do not exist. It is not that they are in natural marriages. Civilly they have signed a contract, but because they are also bound by Canon Law as Catholics. It gets confusing in its language because the State does not recognize canon law, so legally they are categorized as married, though naturally they’re not married. Its easy to just confuse sacramental marriage with “oh the priest blesses the marriage.”
But in the end, the reality of gay marriage is this as well. Even if all 50 states legalize gay marriage, the objective reality is that these individuals are not married. It would be like if the state decided that sexual relationship or sexual love was not a componant of marriage. It would be if we just decided that rather than adoption, we decided to have children not biologically related to their adoptive family marry their adopted family. We wouldn’t be expecting a sexual encounter. We just might have culturally started to embrace wedding traditions surrounding adoption and wanted to emphasis the child’s consent to be our children. The rhetoric surrounding the issue might involve treating children as property. “Children should marry their parents to express their love and consent to be their children. They shouldn’t be treated as property.”
Now I don’t think that is going to happen because so much feminist thought still sees the history of marriage as embarrassing and sexist. They often compare marriage to the selling of cattle. I can’t imagine someone arguing that marriage is a more dignified term than adoption. But by expanding adoption to unions outside of what has been traditionally understood as marriage, we lose our word for marriage. That’s why today we tend to add the adjective “traditional” to marriage to clarify our meaning. However “Sacramental” is not an adjective that adequately distinquishes between “traditional marriage” and what we like to call marriage today.