At first civil unions were allowed in several states for same-sex domestic partnerships. Then judges said they were equivalent to civil marriages. Now the U.S. Supreme Court has redefined civil marriage to include same-sex domestic partnerships. Essentially the Court has downgraded civil marriages to civil unions.
States should respond by replacing civil marriages with civil unions. Why? That would be using the correct term. And that would preserve the traditional understanding of marriage as only for a man and a woman. Marriage would be returned to society, to be defined as people use the term and not how five judges want the term used.
Religious wedding ceremonies would still inaugurate marriages, which could be registered as civil unions as well. What about secular people? There are secular religions for them, and social organizations could also hold weddings.
Civil unions need to cover only matters of interest to the state: taxes, property ownership, child custody, inheritance, etc. The social aspects would be left to society, as the religious aspects would be left to religious organizations. Marriages would be society’s business, not the state’s business.