It's unusual when the winners of a case ask the U.S. Supreme Court to hear an appeal of their victory. But that is exactly the plea being made by lawyers for same-sex couples who successfully challenged bans on such unions in Virginia, Oklahoma and Utah. And for good reasons.

Although some same-sex couples have been able to enjoy the protections of marriage because of lower-court decisions, others are unable to marry because rulings in their favor have been stayed pending the outcome of appeals. (Then there are the gay couples in Utah who wed after a federal judge struck down a ban on same-sex marriage but before his ruling was stayed.)

The country wouldn't be in this position if the Supreme Court had issued a straightforward ruling last year holding that bans on same-sex marriage violate the Constitution's guarantees of due process and equal protection of the laws. But the court sidestepped that issue when it ruled that proponents of California's Proposition 8 lacked standing to appeal a lower-court ruling striking it down.

That had the welcome practical effect of permitting the resumption of same-sex marriages in California, but it set no national precedent. Nor did a decision handed down the same day in which the court invalidated a section of the Defense of Marriage Act defining marriage for federal purposes as the union of one man and one woman.

Justice Anthony M. Kennedy's majority opinion concluded that DOMA's refusal to recognize same-sex marriages that were legal under state law imposed a stigma on same-sex couples — an observation that could also be made about state laws against gay marriage. But Kennedy also emphasized the fact that, traditionally, states have had the authority to define marriage.

Federal judges who have invalidated bans on same-sex marriage have focused on the first theme in Kennedy's opinion, but only the Supreme Court — with Kennedy as the likely deciding vote — can say conclusively whether those judges correctly read between the lines.

It's now time for the nation's highest court to rule unambiguously that gay couples are equal under the law.