Marriage is a contract between two consenting adults.
In America, we have a long history of law regarding contracts and any two adults can enter into legally enforceable contracts without the participation of government in advance. Two people can own property together, commonly. Two people can hold assets commonly and dispose of them commonly. Two people can share ownership of all forms of tangible and intangible assets, they can exchange documents granting power of attorney, they can designate each other policy beneficiaries, create living and final wills designating each other the custodian, executor and beneficiary.
In short, two people can enter into a partnership, even a domestic partnership, that is enforceable by law by adopting the proper legal structures, and exchanging appropriate legal documents without advance approval of the government. There is more than adequate experience for the courts to resolve any questions arising from this arrangement should a breach occur that is cause for termination. The government does not have any need to become involved until the partnership is dissolved, in what ever way that occurs. In short, It is not necessary to secure approval in advance from the government to create a partnership.
Marriage is legally different.
Marriage is a contract between two consenting adults, not of the same sex, and the government, representing (potentially) an unknown number of interested third parties, referred to as their children that hold a unique interest that survives the termination of the contract.
It is the interest of this special class of interested third parties created where none previously existed at the time the contracted was executed, with unique rights that survive the termination of the contract that justifies the government involvement in the contract through the process established to issue a marriage license.
It is understood that there are circumstances in which one or more members of a domestic partnership formed by people of the same sex can give birth to a child. When the two people are women either or both could give birth to a child, but not without the participation of a third party. They cannot create an interested third party where none existed within the confines of a monogamous relationship. And the government has numerous laws and substantial legal precedent to protect the rights of a child born out of wedlock. The government has established the enforceability of the implied temporary arrangement (however brief and however distant) between the two biological contributing parties, one male and one female which lead to the pregnancy. The government is interested in enforcing the survivable rights of the offspring against the biological parents exclusively.
Of course there is adoption. Lesbian, gay and heterosexual coupes can adopt a child. Even single people can adopt a child. But again, this requires the participation of a third party, the adoption agency, and is not the product of intimate relations. The government does get involved in the recognition of an adoption agreement specifically to protect those interests of the adopted child that will survive the termination of the partnership should that occur.
So, the evidence is clear that marriage isn't about religion, or love or commitment, but a legal contract protecting the unique interests of (potentially) an unknown number if interested third parties that are created were none existing and that have unique rights that survive the termination of contract that created the partnership into which they are introduced. Children are an expected consequence of the intimate relations between two people of different sexes engaged in a monogamous relationship.
Any intimate relations between two consenting adults that are biologically incapable of producing offspring is just sex. And in America over the last fifty years liberals have worked hard to eliminate any justification for the involvement of the government in any form of regulation of sex occurring between two consenting adults.
It is unnerving to think that people, especially people who have suffered greatly under the disapproving regulations of the government, would suddenly want to yield the authority to the government to condone, and by extension approve or disapprove their sexual relationship. Given that governments change it seems obvious that some things are best left to personal choice, exclusively.
Cross posted at www.Freedoms-light.org