At all. Though I'm further backwards than Roberts - as I don't even affirm a right to marry at all, and would also leave that up to the states.
So no, I don't think homosexuals need a federal right basis (constitutional) for gay marriage. I'd be fine with any given state voting it in, but hate the idea of a SCOTUS mandate pushing it, "If you are among the many Americans—of whateversexual orientation—who favor expanding same-sex marriage, by all means celebrate today’s decision. Celebrate the achievement of a desired goal. Celebrate the opportunity for a new expression of commitment to a partner. Celebrate the availability of new benefits. But do not celebrate the Constitution. It had nothing to do with it.".
Below is long, so feel free to not read, but it's about the mention of Due Process and Equal Protections in the majority argument.
Petitioners first contend that the marriage laws of theirStates violate the Due Process Clause. The Solicitor General of the United States, appearing in support of petitioners, expressly disowned that position before this Court. See Tr. of Oral Arg. on Question 1, at 38–39. The majoritynevertheless resolves these cases for petitioners based
almost entirely on the Due Process Clause.
The majority purports to identify four “principles andtraditions” in this Court’s due process precedents that support a fundamental right for same-sex couples to marry. Ante, at 12. In reality, however, the majority’s approach has no basis in principle or tradition, except for the unprincipled tradition of judicial policymaking that characterized discredited decisions such as Lochner v. New York, 198 U. S. 45. Stripped of its shiny rhetorical gloss, the majority’s argument is that the Due Process Clause gives same-sex couples a fundamental right to marrybecause it will be good for them and for society. If I were a legislator, I would certainly consider that view as a matter of social policy. But as a judge, I find the majority’s position indefensible as a matter of constitutional law.
In addition to their due process argument, petitioners contend that the Equal Protection Clause requires their States to license and recognize same-sex marriages. The majority does not seriously engage with this claim. Its discussion is, quite frankly, difficult to follow. The central point seems to be that there is a “synergy between” the Equal Protection Clause and the Due Process Clause, and that some precedents relying on one Clause have alsorelied on the other. Ante, at 20. Absent from this portionof the opinion, however, is anything resembling our usualframework for deciding equal protection cases. It is casebook doctrine that the “modern Supreme Court’s treatment of equal protection claims has used a means-ends methodology in which judges ask whether the classification the government is using is sufficiently related to thegoals it is pursuing.” G. Stone, L. Seidman, C. Sunstein,
M. Tushnet, & P. Karlan, Constitutional Law 453 (7th ed.
2013). The majority’s approach today is different:
“Rights implicit in liberty and rights secured by equal protection may rest on different precepts and are notalways co-extensive, yet in some instances each maybe instructive as to the meaning and reach of the other. In any particular case one Clause may be thought to capture the essence of the right in a more accurate and comprehensive way, even as the twoClauses may converge in the identification and definition of the right.” Ante, at 19.
The majority goes on to assert in conclusory fashion thatthe Equal Protection Clause provides an alternative basis for its holding. Ante, at 22. Yet the majority fails to provide even a single sentence explaining how the Equal
Protection Clause supplies independent weight for its position, nor does it attempt to justify its gratuitous violation of the canon against unnecessarily resolving constitutional questions. See Northwest Austin Municipal Util. Dist. No. One v. Holder, 557 U. S. 193, 197 (2009). In any event, the marriage laws at issue here do not violate theEqual Protection Clause, because distinguishing between opposite-sex and same-sex couples is rationally related to the States’ “legitimate state interest” in “preserving the traditional institution of marriage.” Lawrence, 539 U. S., at 585 (O’Connor, J., concurring in judgment).