See the 9th Amendment: "The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people."
That's why.
Whether or not marriage is a "right," its exlusion from the list of rights enumerated in the Bill of Rights is no argument for claiming that it isn't.
"Whether or not marriage is a "right," its exlusion from the list of rights enumerated in the Bill of Rights is no argument for claiming that it isn't."
It's a moot point anyway. No citizen of this country can legally marry a member of the same sex.