From what I can tell, the ruling went the way it did because the plaintiffs (anti-Prop. 8) were prepared to make their case while the proponents (pro-Prop. 8) were not. The plaintiffs put forward eight lay witnesses, including the plaintiffs themselves (Kristin Perry, Sandra Stier, Jeffrey Zarrillo and Paul Katami). They also put forward nine expert witnesses, all of whom had Ph.D.s and had published peer-reviewed articles in the fields relevant to the case.
The proponents (pro-Prop. 8), on the other hand, only ended up putting forward two expert witnesses. On the first day of trial they announced they were withdrawing four of their expert witnesses because the witnesses were "concerned about their personal safety, and did not want to appear with any recording of any sort, whatsoever." So in response to their concern the judge stopped all public broadcasting of the trial. Yet the proponents never called upon these four witnesses even after public broadcasting was banned from the court, and gave no explanation why.
Interestingly, the plaintiffs were able to enter into evidence the deposition testimony of two of the proponents' withdrawn witnesses, "because their testimony supported the plaintiffs' claims." Katherine Young (Ph.D. in history of religions and comparative religions) of the proponents' side stated in her deposition that homosexuality is a normal variant of human sexuality and that same sex couples express the same desire for love and commitment as opposite sex couples. Paul Nathanson (Ph.D. in religious studies), also of the proponents' side, testified at his deposition that religion lies at the heart of the hostility and violence directed at gays and lesbians, and that there is no evidence that children who are raised by same-sex couples fare worse than those raised by opposite sex couples.
The two expert witnesses that remained for the proponents were David Blankenhorn and Kenneth P. Miller. I guess Blankenhorn was now going to be their star witness, except that the judge had to throw out his testimony as unreliable. The main problem with Blankenhorn from the start was that he didn't have a degree in psychology, sociology or anthropology (he had a B.A. in social studies and an M.A. in social history), and he didn't have any peer-reviewed articles published in the areas that related to the case. His credentials simply paled in comparison to that of the expert witnesses on the plaintiffs' side.
The judge let him testify anyhow and found several problems with his testimony. Blankenhorn could not explain the methodology he used to arrive at his opinions, would merely quote from others to support his opinions without citing sources, made reference to research that did not support his claims, contradicted himself a lot, and refused to directly answer many questions upon cross examination. Here's a sample of one of the bizarre exchanges that took place: Blankenhorn says there are three universal rules that govern marriage: the rule of opposites (man/woman), the rule of two people, and the rule of sex. Even a polygamous marriage, he says, does not violate the rule of two.
Q: Is it your view that that man who has married one wife, and then another wife, and then another wife, and then another wife, and then another wife, and now has five wives, and they are all his wives at the same time, that that marriage is consistent with your rule of two?
A (Blankenhorn): I concur with Bronislaw Malinowski, and others, who say that that is consistent with the two rule of marriage."
Blankenhorn was also questioned about something he wrote in 2007: "I believe that today the principle of equal human dignity must apply to gay and lesbian persons. In that sense, insofar as we are a nation founded on this principle, we would be more American on the day we permitted same-sex marriage than we were the day before." Blankenhorn testified that he wrote the statement and agreed with it. With all the unsupportable, contradictory and bizarre statements Blankenhorn was making, it's no wonder the judge found his testimony unreliable.
The second expert witness put forward by the proponents, Kenneth P. Miller (Ph.D. in political science), testified on the political power of gays and lesbians. The court found that "while Miller has significant experience with politics generally, he is not sufficiently familiar with gay and lesbian politics specifically to offer opinions on gay and lesbian political power." Miller's main argument was to point to political successes for gays and lesbians in California to show how they possessed significant political power. He admitted, however, that he has never focused his research specifically on gay and lesbian issues. He could not comment on anti-discrimination laws, anti-gay harassment at workplaces and schools, gay political power as compared with African-American political power, or explain his claim that religious groups support gays and lesbians when the polling data shows that 84% of regular churchgoers voted yes on Prop. 8. The judge wasn't as harsh with Miller as with Blankenhorn, but still found Miller's opinions to be of "little weight."
So you can see where all this is going. The proponents have utterly failed to make their case, leaving the door wide open for the plaintiffs to make theirs. But not only did they fail to make a case, the judge also noted that the proponents presented a very different set of arguments before the court than the arguments they presented to the voters in the Yes on 8 Campaign. No one on the proponents' side attempted to explain this discrepancy.
Next up, I'll attempt to sum up the evidence the plaintiffs presented in support of their case. To be continued...