Thomas Clark, a former editor for the Columbia Law Review and judicial clerk on the US Court of Appeals for the DC Circuit takes on Judge Walker's gravely flawed arguments in Perry V. Schwarzenegger. The entire article is worth reading but here are the highlights:

Walker realizes he has to engage in some clever sleight-of-hand to overcome the fact that same-sex marriage has not only never been recognized as a fundamental right under the U.S. Constitution, but indeed had never even existed in the United States until 2004.

... [On the misappropriation of Loving v. Virginia to argue for SSM] Marriage as a union of man and woman for the purpose of procreation, far from being an irrelevancy to the Loving Court, was an assumption too obvious to need stating—and indeed was what rendered the ban on interracial marriage particularly invidious.

... [On the false gender equality argument] It should be obvious that this distinction between genders, and consequent difference in the ramifications of same-sex and opposite-sex unions, need imply no inequality among the genders. The regrettable past invoked by Judge Walker, including the doctrine of coverture, by which a woman’s assets and legal identity were “subsumed” under her husband’s upon marriage, indeed “is passed” and rightly so. But the correction of this past inequality means assuring equal legal standing and protections for the rights of men and women in marriage, not the legal pretense that all aspects of masculine and feminine nature are to be obliterated or ignored.

... [On Walker's irrational claim of "no rational basis" for Prop 8] "Walker is callous in his summary dismissal of proponents’ arguments. Proponents submitted briefs and testimony that Proposition 8 would at least arguably serve the purposes of (1) promoting stability and responsibility in naturally procreative relationships, (2) promoting enduring and stable family structures for the responsible raising and care of children by their biological parents, (3) increasing the probability that natural procreation will occur within stable, enduring, and supporting family structures, (4) promoting the natural and mutually beneficial bonds between parents and their biological children, (5) increasing the probability that each child will be raised by both of his or her biological parents, (6) increasing the probability that each child will be raised by both a father and a mother, and (7) increasing the probability that each child will have a legally recognized father and mother.

... [On religion and nature being the ultimate objects of Walker's attack] So what exactly is the purpose of these extensive fact findings on the doctrinal tenets of major Christian groups against homosexuality? Read together with the findings that social acceptance, and not mere legal equality, is the object of plaintiffs, it becomes increasingly clear that the ground is being laid for an assault on the perceived obstacles to full acceptance of the homosexual lifestyle, which are two. First, as Walker already has quoted Segura to explain, is religion, and specifically the religious world view adopted by the above-quoted tenets that provide for a moral norm under which homosexual marriage would contravene the common good. Second, and closely aligned to it, is the natural fact that these world views interpret as counter-indicating homosexuality, namely, the sexual complementarity of man and woman.

Clark's conclusion:

Perry aims a dagger at the heart of marriage as we know it. Taking it at its word and applying principles of consistency and logic, it cannot help but result in the expansion of marriage until it encompasses bigamy, incest, wider groupings of association, and finally loses its meaning. As regrettable as this would be, it might be preferable to a regime that insisted on a sacred marriage based on sexual intimacy, but did so in a way that tried to obliterate any distinction based on gender. What would follow would inevitably be a gradual delinking of marriage and intimacy from biological procreation, and the substitution of technological means and commercialized surrogacy for traditional biological mother-and-father-based families. Ultimately, the temptation would arise for the state to take over the role of assigning children to suitable “parents,” since biological ties would no longer be recognized as dispositive. The likelihood of this progression of events can be reduced by recognizing the rationality and validity of traditional one-man-one-woman marriage and defending it. Stopping the dangerous logic of Perry in its tracks is the place to start, ideally by judicial reversal, if necessary by other constitutional means.