There are two aspects of marriage – the civil aspect and the religious aspect. Often, discussion of same-sex marriage conflates these two aspects, ignoring the separation of church and state that is guaranteed by the first amendment to the US Constitution. This issue is exacerbated by the fact that clergy people often act as proxies for the state by consummating the civil portion concurrently with the religious ceremony.
Proponents of same-sex marriage do not advocate requiring religious institutions to recognize those marriages if they conflict with the religion’s tenets. But conversely, some religious blocs are imposing their tenets on the civil aspect of marriage – in violation of the First and Fourteenth Amendments.
What is a Civil marriage? It is a contract between two individuals – usually of opposite sex with a few limited exceptions in some states. The contract imposes financial obligations as well as certain rights for each of the partners. Nothing more, nothing less. Indeed, over the years some people have taken advantage of this traditional civil marriage paradigm to enhance immigration status, grab inheritance (see, for example, Anna Nicole Smith), and for other less-than-ideal circumstances. These instances certainly don’t promote what the right-wingers have invented as the “sanctity of marriage.”
If it is the will of the people to legalize civil marriage (and it certainly is), then it should be done in compliance with the fourteenth amendment which states (in part) “No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.”
Thus, there is no legal basis for any of the 50 states which allow civil marriages to restrict those covenants to “one man – one woman”. If the legislators continue to impose the unconstitutional restriction on same-sex marriage, then the courts should shoot those laws down.