Summarize this Fourth and finally, this Court's cases and the Nation's traditions make clear that marriage is a keystone of our social order.... This idea has been reiterated even as the institution has evolved in substantial ways over time, superseding rules related to parental consent, gender, and race once thought by many to be essential.... For that reason, just as a couple vows to support each other, so does society pledge to support the couple, offering symbolic recognition and material benefits to protect and nourish the union.... These aspects of marital status include: taxation; inheritance and property rights; rules of intestate succession; spousal privilege in the law of evidence; hospital access; medical decisionmaking authority; adoption rights; the rights and benefits of survivors; birth and death certificates; professional ethics rules; campaign finance restrictions; workers' compensation benefits; health insurance; and child custody, support, and visitation rules.... ... The limitation of marriage to opposite-sex couples may long have seemed natural and just, but its inconsistency with the central meaning of the fundamental right to marry is now manifest. With that knowledge must come the recognition that laws excluding same-sex couples from the marriage right impose stigma and injury of the kind prohibited by our basic charter