More the reverse - because it has no claim to it in the first place. Marriage is a contract, yes, but one based on love and a pledge before God. Government can only rule what it can reach. So how, exactly, is the government going to decide upon the legitimacy of two people's love? How is it going to rule on the legitimacy of two people's pledge to God?
Yes, it can pretend to do so. But my position is that that's all it is - pretending. That, in fact, Government cannot reach love or devotion to God. These things are inherent in natural human beings, which are put above the government by the Constitution. They are not defined in a statute or regulation and applied as privileges to people - they are innate.
And, therefore, marriage as defined as including, let alone being based on, love for one another and devotion to God, is simply outside of the jurisdiction of the government - literally out of the reach of the law. Fundamentally, and forever.
All of that could be true, but we still end up, if we go government out of the marriage business route, with same sex married couples. I’m not sure what the benefit is.