“The state doesn’t have an interest in love and emotion at all,” Mr. Bursch said. “It’s about binding children to their biological moms and dads.”
Several justices were intensely skeptical of that rationale, noting that many gay couples have children. These justices also seemed unpersuaded by Mr. Bursch’s contention that altering the definition of marriage would harm the institution.
This has to be the weakest argument they could choose. It's so limiting. It also leads to this argument: If marriage is about "binding children to their biological moms and dads” then should people who do not want children, or cannot have children even be allowed to marry? If this argument is accepted then wouldn't that redefine marriage, far more than gay marriage? It also merges quite nicely with the Republican's forced birth-anti birth control platform.