My marriage with my wife is our business. We chose to involve family, friends, and a minister at an event to memorialize this union, but that was our choice and no business whatsoever of the state or federal government.
Marriage is not a state event. Relationships between individuals are not up to bureaucrats, central planners or a majority of the voters, but strictly the business of the individuals in that relationship. While the governor or legislature of Idaho may have opinions of what marriages they like, there is no room whatsoever in their job descriptions for dictating relationships to the people of the state.
In 1789 the United States of America began life as a republic under our current Constitution. The men who formed this republic studied government structures, successes and failures from throughout the recorded history of our world. They knew that democracies, like a lamb and two wolves voting on what’s for dinner, are short-lived. Our republic, bound by laws limiting what the majority of the voters could do to the minority, was one of the most successful innovations in European culture.
A democracy allows the majority to throw Christians to the lions. A republic does not. In a democracy the majority can condone some relationships and condemn others. In a republic a hospital patient can be visited by their best friend and life partner whether or not the majority approve of their relationship. In a republic two people can together enter into a contract for a home mortgage without state approval. In a republic you are protected by law from majority disapproval, or even assaults by powerful or vocal minorities. In a democracy, you are not.
In a libertarian world, the government has no business in defining or sanctioning relationships. Churches, families and communities do that. We are 225 years beyond that original libertarian USA, but I sure hope we aren’t so far gone as to legislate against minority relationships.