"I think there's substance to the point that sociological information is new. We have five years of information to weigh against 2,000 years of history or more," Kennedy said to Ted Olson, the lawyer pushing to strike down Prop 8. "On the other hand, there is an immediate legal injury or legal -- what could be a legal injury, and that's the voice of these children. There are some 40,000 children in California, according to the Red Brief, that live with same-sex parents, and they want their parents to have full recognition and full status. The voice of those children is important in this case, don't you think?"
Liberal-leaning Justices Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor and Elena Kagan appeared skeptical that state bans on same-sex marriage were permissible under the Constitution's equal protection clause.
"Outside of the marriage context," Sotomayor asked the lawyer defending Prop 8, Charles Cooper, "can you think of any other rational basis, reason, for a state using sexual orientation as a factor in denying homosexuals benefits or imposing burdens on them?"
Kagan asked Cooper "what harm you see happening ... what harm to the institution of marriage or to opposite-sex couples" if gays and lesbians are allowed to marry. "Is there any reason you have for excluding them?" she asked.
Justice Antonin Scalia jumped in to defend Prop 8 when Cooper was unable to provide specific harm that would be done by allowing same sex couples to marry.
"Mr. Cooper, let me give you one concrete thing. I don't know why you don't mention some concrete things," he said. "If you redefine marriage to include same-sex couples, you must permit adoption by same-sex couples, and there's considerable disagreement among sociologists as to what the consequences of raising a child in a single-sex family, whether that is harmful to the child or not. Some states do not permit adoption by same-sex couples for that reason."
For his part, Chief Justice John Roberts asked multiple skeptical questions of Prop 8's challengers, signaling sympathy with it as a valid exercise of state power.
"I'm not sure that it's right to view this as excluding a particular group," Roberts said. "Same-sex couples have every other right, it's just about the label."
Justice Samuel Alito declared that same-sex marriage is "newer than cell phones or the Internet" and argued that it should be left to the voters. "On a question like that, of such fundamental importance," he said, "why should it not be left for the people, either acting through initiatives and referendums or through their elected public officials?"
Justice Clarence Thomas did not speak, but is expected to side with the conservatives.