Jonathan Rauch argues for a minimalist finding, in a letter to SCOTUS:
Gay Americans are in sight of winning marriage not merely as a gift of five referees but in public competition against the all the arguments and money our opponents can throw at us. A Supreme Court intervention now would deprive us of that victory. Our right to marry would never enjoy the deep legitimacy that only a popular mandate can bring....
In the California marriage case, you certainly don’t lack for options. You could give gay-marriage opponents a home run, foreclosing gay couples’ constitutional claim for decades to come—a tragic setback, from a gay point of view. You could give gay-marriage supporters a home run, as a California district court did. You could uphold the narrower opinion of the Ninth Circuit federal appeals court, which overturned California’s ban on gay marriage but would have no practical effect in other states.
Or you could do something you hinted at in your decision to take the case, when you asked to be briefed on whether the parties have standing to sue. That is, you could rule that the case was improperly brought and isn’t ripe for any kind of ruling. Though the precise legal consequences would depend on how you wrote the fine print, the basic effect would be to defer the constitutional battle over gay marriage until a later day.
That day will come. We can even guess when. In 1948, California’s supreme court overturned the state’s ban on interracial marriage. It took the U.S. Supreme Court 19 years to affirm and nationalize that ruling, and by then the decision wasn’t controversial. In 1993, Congress banned openly gay people from serving in the U.S. armed forces. It took the courts and Congress 17 years to repeal that ban, and by then the decision wasn’t controversial. You see the pattern. Massachusetts enacted gay marriage in 2004. If the past is prologue, by the early 2020s the country will have reached a consensus on same-sex marriage.I think there is no chance the court will find broadly. I have hopes for a narrow overturn of Prop8, but I have a bad feeling that it won't happen.
I think that they will uphold Prop8 and knockout DOMA's clause 3, based on the same arguments: the states' rights to determine marriage.
That's my bet.