The state should not ban same-sex marriage.

Before I begin, I offer a brief observation. The Original Position presumes the universality and truth of philosophical liberalism. In other words, people are considered atomistic units with a negative right to liberty that specifies, but is not necessarily limited to, non-interference. This means that no Communitarian ideas can be used in this round, and cultural norms cannot be discussed or taken into account when making this decision. This debate is purely concerned with Justice.
Marriage is defined as a social union between spouses that creates kinship [1]. Marriage is furthermore a union in which intimate interpersonal relationships are acknowledged [1]. This definition of marriage is most accurate because it best accounts for all types of marriages across a variety of cultures from different eras (in other words, it is universal). Nonprocreative relationships, same sex unions in places such as Ancient Rome (when Emperor Nero married another male), China, and polyandrous and polygamous marriages are all covered by this definition.
I contend that the state may not ban same-sex marriage because to do so would be to arbitrarily interfere with the right to liberty.
The right to liberty exists because people belong to themselves. The notion that we own ourselves stems from our ability to give our lives meaning. We hold our lives to be meaningful insofar as we are able to pursue our own aspirations independently of social impact and external pressures. Since nothing is objectively meaningful, controlling another individual’s person reduces that individual to meaninglessness since an individual who is unable to pursue his own ends is unable to make his life meaningful to himself. Since all humans wish to live meaningful lives, we create a contractual basis for self-ownership; i.e. self-ownership must exist in order to ensure that all people are able to discover meaningful lives without being subject to the whims of others.
Since people are self-owners and do not belong to others, including their communities, churches, families, friends, enemies, and other acquaintances and social institutions, they have a right to do as they please so long as they do not interfere with the rights of others. The contractual basis for self-ownership stipulates that we are free to do whatever we please to ourselves, but that because we are obligated to respect the bodily integrity of others, our right to liberty does not permit us to do whatever we please to them without their consent. Therefore, a major aspect of the right to liberty centers on noninterference. In other words, a major aspect of liberty is negative and entails that other people cannot infringe on my liberty.
Any marriage, or relationship that creates ties of kinship, that occurs between two consenting adults is, by its nature, an expression of the right to liberty, and thus cannot be restricted by others. I am free to submit to a tie of kinship or an intimate relationship with any other individual so long as he or she consents to take part in the relationship. If others attempt to restrict my ability to create an intimate relationship with another, he or she is violating my right to liberty insofar as he is restricting what I can do with my body and person and insofar as he is preventing me from pursuing my own ends.
The state, by definition, is the embodiment of communal authority. We consent to a state, and indeed a society, in order to create an enforcement mechanism for our liberty through a social contract. A social contract is an agreement between the citizens and the state that is based on reciprocity. The citizens in society agree to follow the state’s laws in exchange for the protection of their natural rights. Therefore, a just state may only restrict liberty to protect the liberty of others since restricting it would cause the state to violate one’s natural rights rather than enforcing them. Since same sex marriage does not violate the liberty of others, the state has absolutely no grounds for abrogating such marriages. Moreover, since the state is a representative of the people within the community, it has the same obligations that people within that community have. Therefore, it has the same obligation to respect an individual’s choice to obtain a same-sex marriage that its constituency has.
Thus, the state should not ban same-sex marriage.

Sources
1. http://en.wikipedia.org...