EVERYONE seems to think the Supreme Court will declare a constitutional right to same-sex marriage this June. And so it may. But allthepredictions, registered before the justices have even heard oral arguments on April 28th in four challenges to state gay marriage bans, are a bit premature. The case for finding a right to gay nuptials in the 14th amendment, which we outlined last week, is indeed strong. But the defences of bans in Michigan, Ohio, Kentucky and Tennessee merit close consideration and will no doubt earn such a reading from the expected swing vote, Justice Anthony Kennedy. The reasons on offer for upholding heterosexual marriage rules are a far cry from the preachy, Leviticus-quoting diatribes of receding memory. The merits briefs from the four states do not moralise. They betray no ill-will toward gays and lesbians. The respondents in the Michigan and Kentucky cases, in particular, readily admit that Americans’ views on marriage are changing. Michigan acknowledges that “people have many different understandings of marriage and the role it should play in society.” The Wolverine state’s brief even references a recent book by Michael Klarman, a Harvard law school professor, suggesting, with statistical analysis, that all 50 states “will legislatively adopt” same-sex marriage “within 10 years if the political process is left to run its course.”

The crux of the argument in defence of the same-sex marriage bans is that a Supreme Court ruling could short-circuit the political process. Judicial fiat would thwart the will of the people. The argument against same-sex marriage is thus reduced from full-throated condemnation to a critique of judicial activism and the harms to democracy and federalism that a pro-gay marriage ruling would inflict. “The petitioners seek to end the democratic debate,” Kentucky’s brief accuses. “They ask this court wholly to remove the states’ role—the citizens’ role—in defining marriage through the democratic process.”

Democracy is, we can posit, a wonderful thing. But as Justice Robert Jackson wrote in 1943, “the very purpose of a Bill of Rights was to withdraw certain subjects from the vicissitudes of political controversy, to place them beyond the reach of majorities and officials, and to establish them as legal principles to be applied by the courts.” If gay marriage is one of those subjects, the Supreme Court has a responsibility to take the issue out of voters' hands. There are two jurisprudential avenues by which the justices could make gay marriage a constitutional right. Both are found in the 14th amendment.

One is the “due process clause”, which says that the state may not strip citizens of “life, liberty or property” without good cause. In order to lend concrete meaning to the capacious term “liberty,” the Supreme Court over the decades has used two tests. Rights are “fundamental,” and thus deserve protection, the justices have held, if they are either “deeply rooted in the Nation’s history and tradition,” or “implicit in the concept of ordered liberty.” Any of the rights specifically enshrined in the Constitution count as “fundamental,” as do the right to privacy (embracing contraceptive and abortion rights) and, crucially, the right to marry. But Kentucky insists that this right is limited to opposite-sex couples and does not entail “a fundamental right to marry any person.” And Michigan warns that a win for the petitioners would open the floodgates on challenges to “other longstanding marriage limitations” involving, for example, “underage couples.” Appeals from polygamists and incest aficionados loom right over the horizon, the brief implied.

The second possible source for the right gay couples are seeking is in the “equal protection clause,” which prohibits certain types of discriminatory treatment, especially when it is inflicted on a “discrete and insular minority” that has suffered a history of mistreatment and political weakness (ie, a “suspect class”). Gays and lesbians, the briefs contend, may once have been treated poorly but today are hardly powerless. Over 50% of Americans now support same-sex marriage, gays “attract the attention of lawmakers” and they have “no obvious, immutable or distinguishing traits.” Most significantly, the marriage laws are not, the states insist, based on “animus” toward gays. They are benign attempts to encourage heterosexual couples to sanctify and stabilise their relationships for the benefit of potential offspring.

The obvious counter-charge to this asserted state interest is that plenty of gay couples have children while many straight couples do not. Why let an infertile or postmenopausal woman marry a man, but begrudge a wedding ceremony for a lesbian couple anxious to have kids? The briefs have something of an answer, but it won’t fit on a bumper sticker. The law in Kentucky is ”rationally related to the state’s interest in furthering procreation,” even if it does not pursue that interest comprehensively, and even if it permits marriages for couples lacking the will or the ability to reproduce. Both briefs quote a case from 1979 that permits a state to withhold a benefit from some when it provides it to others: “[e]ven if [a] classification...is to some extent both underinclusive and overinclusive, and hence the line drawn by [the legislature or people] is imperfect, it is nevertheless the rule that in [rational-basis review] ‘perfection is by no means required.’"

That’s hardly a ringing endorsement of same-sex marriage bans. It amounts to this: voters can prevent fellow citizens from marrying if they want to, full stop. Voters don’t need to have much of a reason, and they can rope out gays who intend to raise families and include straights who do not because, well, gays are not a “suspect class” worthy of heightened scrutiny. Any old reason for the ban will do. “The people themselves”—voters—should enjoy “the benefit of every doubt,” Michigan argues.

The states' arguments taste of rather weak tea, but the line-drawing point should give pause to even the liberal justices. In framing their view as one of "marriage equality", and in urging a shift from procreation to state-recognised intimacy as the basis of marriage, the challengers of the state bans open themselves up to worries about where this all ends. We don't have to revert to Rick Santorum's ridiculous comparison of homosexuality to "man on child, man on dog, or whatever the case may be" to imagine polygamists pressing for their day in court were the justices to affirm a new constitutional right to same-sex marriage. There may be much better policy arguments for a ban on polygamy than for prohibitions on gay marriage (and there certainly are strong state interests in maintaining age-of-consent laws) so the worry is not that handing gays and lesbians this new right will destroy marriage as we know it. But the issue will come up, and the justices need to find a way to expand the boundaries of marriage without erasing them.

The most profound weakness inherent in the respondents’ position is its apparent heartlessness. In advancing a procedural argument about how a constitutional democracy best functions—with average people, not judges, dictating the nature and pace of social change—Michigan and Kentucky are long on political theory and short on real life. Unlike other hot-button constitutional controversies, conservatives have a hopeless public-relations war to wage. The best they can do, as Michigan did, is to append a table showing “ballot-box votes on the definition of marriage” that a ruling in favour of same-sex marriage would overturn. There are no poster children to be found. Supporters of the death penalty recall gory stories of murder victims, whose killers, they say, deserve the ultimate punishment; affirmative action opponents point to jilted white or Asian candidates who are rejected from their top-choice university because minority applicants with inferior credentials got in; and pro-life activists stick photos of aborted fetuses in women’s faces. But there is just no vivid argument available to match the stories of couples who cannot file a joint tax return, visit one another in the hospital or adopt each others’ children. No innocent bystander was ever dealt an injustice, maimed or killed because a pair of doting gays or lesbians happened to get hitched.

Dig deeper:

Read our write-up of the merit briefs in favour of same-sex marriage