The other shoe has dropped for same-sex marriage.

The first hit the floor last November, when the Sixth Circuit upheld the “traditional marriage” restrictions in four states, thus creating a split among the federal circuits.

This was exactly what was not present a month earlier, when the Supreme Court let stand lower courts’ rulings on the same issue. Back then, Justice Ginsberg said, “there is no need to rush.”

But once the Sixth Circuit diverged from the opinions of the 4th, 7th, 9th, and 10th, such a need arose—if not to rush, then at least to decide the matter, perhaps once and for all.

That need was answered today, as the Supreme Court agreed to take up four cases (now consolidated into one) challenging state marriage bans. Oral argument will be in April and May, and the decision likely rendered in June.

For now, let the tea-leaf-reading begin.

On the one hand, same sex marriage has been described as “inevitable” by many august legal pundits (including this one). It is legal in 35 states plus the District of Columbia, with nine more states in the appeals process, and four now at the Supreme Court Bar. That’s just about everywhere.

Heck, even conservatives have grudgingly come around. Several of the recent judicial opinions upholding marriage equality have been written by conservative judges.

Republicans including George H.W. Bush, Dick Cheney, and Laura Bush are on board. Even Christian Right poster boy Kirk Cameron said Christians should blame themselves, not others, for the “decay” in marriage—an analysis borne out by economic data.

On the other hand, there are several signs that indicate this may turn into yet another partisan battle, with Justice Kennedy deciding once again.

First, Justice Thomas said in an official statement that he would’ve liked the Court to take up the marriage cases last fall. “For reasons that escape me,” he said, “we have not done so.” No matter how inevitable same-sex marriage may seem, ultimately the decision will come down to these nine judges.

Second, the Court has bifurcated the current appeal into two distinct questions: first, “Does the Fourteenth Amendment require a state to license a marriage between two people of the same sex?” and second, “Does the Fourteenth Amendment require a state to recognize a marriage between two people of the same sex when their marriage was lawfully licensed and performed out-of-state?”

These are legitimately distinct legal questions. Yet if we are looking for signs and portents, the fact that the Court has so clearly teased them apart indicates that it might rule one way on the former question, another way on the latter. That kind of “split the baby” reasoning would be of a piece with the current court’s judicial conservatism—especially that of Justice Kennedy himself.

Third, and most importantly, the actual holding in Windsor—the case that invalidated the Defense of Marriage Act and got the ball rolling on same sex marriage—was actually far more narrowly written than the way it has been construed by lower courts. Although the precise connection between the two arguments of Justice Kennedy’s majority opinion was not entirely clear—indeed, Justice Scalia called it “argle bargle”—the fact is that federalism (and the traditional role of the states in defining the ambit of marriage) had as much to do with the result as did the Fourteenth Amendment.

Subsequent judicial opinions have largely ignored this point, focusing instead on Justice Kennedy’s holding that there was no rational basis for DOMA’s discriminatory measures. And if there’s no rational basis for DOMA, there’s no rational basis for state laws either.

To be sure, the Sixth Circuit, now under review, provided not one but a half dozen such bases. And here are those bases: Allowing the democratic process to proceed, that state marriage laws are not a federal question at all, constitutional originalism, natural law, multiple motivations for anti-gay laws, gay people are not a ‘discrete and insular’ class, and that the meaning of marriage only evolves when the majority says it does.

But with concerns of federalism cutting the other way—that is, in favor of allowing state definitions to stand—perhaps a more important question is whether that’s the right standard of review at all.

While same-sex marriage may seem like a social inevitability at this point, it is not a judicial slam-dunk—not without expanding Windsor, anyway, which Justice Kennedy may or may not be interested in doing. Certainly, it would seem that with the hardcore conservatives on the court—Scalia, Alito, and Thomas—there are ample bases for ruling against marriage equality. Probably for Chief Justice Roberts too.

So it probably will come down to Justice Kennedy, again.

This, in the final analysis, may be good for the gays. In his series of opinions on LGBT issues, Justice Kennedy has taken what might be called a contextual jurisprudential approach to the cases before him. Like the more liberal justices, he seems acutely aware of the reality of anti-gay discrimination—even if, like the more conservative ones, he is keen to maintain a somewhat cautious mode of constitutional reasoning. Put less charitably, Justice Kennedy sometimes seems as though he’s finding a conservative way to do the right liberal thing.

Or perhaps that’s not uncharitable at all. Maybe it’s simply to say he is motivated by justice as well as jurisprudence.

In either case, if a similar pattern holds in this year’s cases, the jurisprudential niceties may not matter so much. If Justice Kennedy is the swing vote, and if he is as motivated by the actual lives of same-sex couples as he seems to be, then broader concerns of justice and history might take precedence over doctrinal reasoning.

And depending on your point of view, that might be the way justice unfolds.