But the opinions, I believe, should convince a reasonable person that constitutional law, and therefore courts, have a legitimate role to play in this divisive area, at least sometimes, standing up for minorities who are at risk in the majoritarian political process.
The future of marriage looks, in one way, a lot like its past. People will continue to unite, form families, have children, and, sometimes, split up. What the Constitution dictates, however, is that whatever the state decides to do in this area will be done on a basis of equality. Government cannot exclude any group of citizens from the civil benefits or the expressive dignities of marriage without a compelling public interest. The full inclusion of same-sex couples is in one sense a large change, just as official recognition of interracial marriage was a large change, and just as the full inclusion of women and African Americans as voters and citizens was a large change. On the other hand, those changes are best seen as a true realization of the promise contained in our constitutional guarantees. We should view this change in the same way. The politics of humanity asks us to stop viewing same-sex marriage as a source of taint or defilement to traditional marriage but, instead, to understand the human purposes of those who seek marriage and the similarity of what they seek to that which straight people seek. When we think this way, the issue ought to look like the miscegenation issue: as an exclusion we can no longer tolerate in a society pursuing equal respect and justice for all.
A long but excellent critique by Martha Nussbaum of the legal rights involved in marriage and how the state plays such a pivotal role here.