Thanks to Norma for a link to a Wall Street Journal! op-ed by David Boies, who's joined in unlikely legal venture with Ted Olson to strike down state bans on same-sex marriage. The precedents are compelling -- bans on marrige of imprisoned felons, child support scofflaws and mixed race couples have fallen before.
There were legitimate state policies that supported the Wisconsin and Missouri restrictions held unconstitutional. By contrast, there is no legitimate state policy underlying Proposition 8. The occasional suggestion that marriages between people of different sexes may somehow be threatened by marriages of people of the same sex does not withstand discussion. It is difficult to the point of impossibility to envision two love-struck heterosexuals contemplating marriage to decide against it because gays and lesbians also have the right to marry; it is equally hard to envision a couple whose marriage is troubled basing the decision of whether to divorce on whether their gay neighbors are married or living in a domestic partnership. And even if depriving lesbians of the right to marry each other could force them into marrying someone they do not love but who happens to be of the opposite sex, it is impossible to see how that could be thought to be as likely to lead to a stable, loving relationship as a marriage to the person they do love.
... The argument in favor of Proposition 8 ultimately comes down to no more than the tautological assertion that a marriage is between a man and a woman. But a slogan is not a substitute for constitutional analysis. Law is about justice, not bumper stickers.