The justices can go to the heart of the matter, whether gay men and lesbians are entitled to the benefits of the equal-protection clause. This would, of course, set off a firestorm among conservatives who argue the 14th Amendment by its terms does not and was not intended to protect gays. This would create as in Roe v. Wade an aggrieved segment of voters who would claim once again that the popular will was subverted by judicial fiat. This is frankly bad for the country and gives opponents of gay marriage an easy out, relieving them of the need to grapple with the fundamental shift in public opinion that has led to popular elections approving gay marriage.
It is possible the 9th Circuit case may be decided on narrower grounds, namely whether it was permissible to take away rights previously granted by the state constitution. That would seem consistent with the judicial principle that courts should be guided by narrow grounds if available.
The other case, from New York, is a “cleaner” issue since the lower-court ruling directly applied DOMA. The Supreme Court could adhere to originality in interpretation and uphold federalism principles by ruling not on the 14th Amendment but on the 10th, finding that the federal government overstepped its bounds in regulating an issue, marriage, which was the traditional province of the states. This would have the benefit of returning the issue to the states, where citizens, whose views have plainly evolved, can decide this issue in the political sphere. This would seem to be the best outcome for all concerned. (As an aside, it would also get Republican candidates for national office out of obsessing on the marriage issue, which is increasing a dead bang loser with voters and a barrier to support from young voters.)
This should be a lesson to social conservatives. By trampling on 10th Amendment principles, rushing to federalize an issue and ignoring public opinion, they now face a devastating loss that would require recognition of gay marriage in all 50 states. When it comes to abortion, they’ve been arguing that the federal courts should get out of regulating reproductive rights and send the issue back to the states. Why isn’t that good enough for marriage as well?