From the SCOTUS Blog here is the analysis of what went down:
Much will be written about the Proposition 8 oral argument. The bottom line, in my opinion, is that the Court probably will not have the five votes necessary to get to any result at all, and almost certainly will not have five votes to decide the merits of whether Proposition 8 is constitutional.
Several Justices seriously doubt whether the petitioners defending Proposition 8 have “standing” to appeal the district court ruling invalidating the measure. These likely include not only more liberal members but also the Chief Justice. If standing is lacking, the Court would vacate the Ninth Circuit’s decision.
The Justices seem divided on the constitutionality of Proposition 8 on ideological lines, four to four – i.e., all the members other than Justice Kennedy. For the more liberal members of the Court, there was no clarity on how broadly they would rule.
But Justice Kennedy seemed very unlikely to provide either side with the fifth vote needed to prevail. He was deeply concerned with the wisdom of acting now when in his view the social science of the effects of same-sex marriage is uncertain because it is so new. He also noted the doubts about the petitioners’ standing. So his suggestion was that the case should be dismissed.
If those features of the oral argument hold up – and I think they will – then the Court’s ruling will take one of two forms. First, a majority (the Chief Justice plus the liberal members of the Court) could decide that the petitioners lack standing. That would vacate the Ninth Circuit’s decision but leave in place the district court decision invalidating Proposition 8. Another case with different petitioners (perhaps a government official who did not want to administer a same-sex marriage) could come to the Supreme Court within two to three years, if the Justices were willing to hear it.So for now Prop 8 is invalid. More to come
Second, the Court may dismiss the case because of an inability to reach a majority. Justice Kennedy takes that view, and Justice Sotomayor indicated that she might join him. Others on the left may agree. That ruling would leave in place the Ninth Circuit’s decision.