One of the secular arguments against allowing same-sex marriage is the argument that marriage is about Responsible Procreation. The essence of that argument, as demonstrated by prominent "marriage defender" David Blankenhorn, is that marriage was designed to produce children and to meet the important social need of childrearing. Leaving aside the question of who, exactly, it was that did this alleged designing, Dreher's piece cites Peter Berkowitz's response to this argument. Namely, even if marriage used to be defined by a man and woman raising their biological children together, marriage is no longer that to many people:
"Ask twentysomethings and thirtysomethings what they hope for from marriage. They will, of course, tell you that they want love and that they definitely want companionship -- indeed, that they expect their spouse to be their best friend. And obviously they want to share the pleasures of sex. Then ask them about children. Many will pause and say well, yes, certainly, they are thinking about children, and eventually, somewhere down the line, they expect to have one or two. But children, once at the center of marriage, have now become negotiable, and what used to be negotiable -- love, companionship, sex -- has moved to the center. Under these circumstances, legal recognition of same-sex marriage will not represent a change in the meaning of a venerable social institution through law, but rather an adaptation of law to a profound change in social meaning." [emphasis added]
That is, legalizing same-sex marriage will not change marriage. It will change the law to reflect what marriage currently is- something along the lines of two people who love each other, commit to mutually supporting each other, and who may or may not raise children together.
Secondly, Dreher cites law professor Amy Wax's secular reasons for opposing marriage equality. I actually take issue with the bulk of Wax's argumentation, as do law professors Dale Carpenter and Andy Koppelman. However, I would especially like to note her argument here:
"Finally... legalizing homosexual marriage will of course create pressure to 'normalize' those relationships in all contexts. This will extend to teaching in public schools (and private schools for that matter).
The absolute equivalence of hetero and homosexual relationships will become public orthodoxy."
I have been doing a fair amount of reading lately on the social construction of outgroups and deviancy. Nothing, I believe, about the anti-gay industry is more harmful to LGBT people than is the idea that we, and our relationships, are inherently pathological and less than heterosexuality and heterosexual relationships. People object to even informing children about homosexuality because they believe in the artificial ideology of heterosexual supremacy.
I know that many heterosexuals and anti-gays believe that their relationships and marriages to their opposite-sex partners are inherently better and more important than my relationship is to my same-sex partner. My partner and I attend weddings of heterosexual friends and family members because we love them; but at the same time I never forget that my "girlfriend" and I have often been together longer than the celebrated bride and groom and, even if we were to have a "commitment ceremony," it would be legally meaningless and would not be universally glorified in the way that heterosexual marriages are.
This isn't an ego thing for gays and lesbians and it's not about hurt feelings. Personally, I don't grant anti-gays that ability, anyway. Heterosexism is more than that. The ideology of heterosexual superiority emphasizes and exaggerates differences between LGBT people and heterosexuals and operates by denying us social acceptance, freedom from stereotypes, freedom from being seen as individuals (as opposed to members of a deviant outgroup), and freedom from being viewed as mentally unwell, pathological, evil, and/or scapegoats for various social ills. It may seem like a lot for parents to give up the "right" to have schools teach that homosexuality is wrong, but I think the benefit to LGBT people of not having to endure this stigma of inferiority outweighs this "right."
Finally, Dreher explores an issue perhaps inherent in the ideology of rights. To many of us who support marriage equality, we do not believe that "marriage defenders" are able to provide a compelling reason as to why same-sex marriage should not be a constitutional right. Yet, to many "marriage defenders," acknowledging the right to same-sex marriage means that we cannot logically deny the right to marriage to other groups seeking marriage, such as polyamorists.
Dale Carpenter, I think, does one of the best jobs of addressing this argument, so I will defer to him:
"One response to the fear that dyadic same-sex unions will lead to a polygamy slippery now is, 'Why would it?' Opening marriage to one change because the change seems justified does not mean that opening marriage to every change is justified. Every proposal for reform rises or falls on its own merits. Gay marriage advocates have made extensive (and contested) arguments about why it would benefit individuals and society. It is up to polygamy advocates to do the same."
Drawing new lines around marriage, does not mean that our legal system is abandoning all lines. The law makes distinctions and these distinctions are upheld unless they are found to be irrelevant or arbitrary. There may, or may not, be large contingents of polyamorists seeking marital rights, but their battle like any other will have to be won on its own merits.
To get around this issue, it is clear that it would be most helpful to all sides to get the government out of this thing called "marriage" entirely. By distributing benefits, rights, and privileges to some personal relationships and not others, the government has set itself up for precisely these sorts of constitutional challenges. Currently, by favoring dyadic heterosexual relationships, the federal government and most states are effectively involved in maintaining an ideology that holds that one type of relationship is superior to every other type of relationship and entitled to public resources that other relationships are not. Combined with the liberal ideology of rights, it will be state involvement in marriage that will be the true destroyer of traditional marriage.