I never see the argument that government should stay out of divorce.
It is not just a states rights issue.
When one state legalizes “same sex marriage”, it has an effect on all the other states, business, etc.
What happens when a gay couple claim they were married in one state, but it is not recognized by other states when they try to file state income taxes as “married”, or the cost to businesses by claiming “health benefits” as “married spouses” .... I can go on and on....