Editor's note: Jeffrey Toobin is CNN senior legal analyst and author of "The Oath: The Obama White House and the Supreme Court." The opinions expressed in this commentary are solely those of the author.
(CNN) -- Same-sex marriage will be the law of the land -- inevitably but not immediately.
That's the message of the Supreme Court's decision today to let stand five federal appellate court rulings that recognized a constitutional right for gay people to marry. The practical effects of today's non-decision are considerable. At a minimum, it means that the five states whose cases were before the court -- Utah, Oklahoma, Virginia, Wisconsin and Indiana -- should allow same-sex marriage immediately.
In addition, the states covered by the circuit courts that include these states will almost certainly now allow same-sex marriages as well. This includes the Fourth Circuit, covering Maryland, Virginia, West Virginia, North Carolina and South Carolina; the Seventh Circuit, including Illinois, Indiana and Wisconsin; and the 10th Circuit, which covers Colorado, Kansas, New Mexico, Oklahoma, Utah and Wyoming.
So for a non-decision, today's non-ruling has a big impact.
The justices never explain why they decline to take a case, but it's possible to offer some informed speculation. It takes only four (of nine) votes for the court to hear a case. So why didn't four justices vote to hear the challenges to the same-sex marriage ban?
The court is polarized, with four conservatives (Chief Justice John Roberts and Justices Antonin Scalia, Clarence Thomas and Samuel Alito) and four liberals (Justices Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor and Elena Kagan), with Anthony Kennedy holding the balance of power, especially on gay rights issues.
It's possible that neither the liberal nor the conservative bloc felt confident enough of Kennedy's vote to risk letting him decide the case. So better to kick the can down the road.
The conservatives have a special reason for delay. Ginsburg, at 81 the oldest justice, will probably leave during the next president's term. A Republican president would replace Ginsburg with a solid conservative vote and make Kennedy's vote irrelevant. So waiting might be an appealing option for them.
The liberals had their own reasons for delay. Same-sex marriage has marched with great speed across the country. Today's non-decision means that more than half the states, with well more than half the population, have marriage equality. Those facts create their own momentum. More time equals more states, which might (the theory goes) make Kennedy's vote easier to get a year from now.
But for now, the state-by-state battles continue. As a result of today's decision, there will not be a 50-state resolution any time soon. But the direction of the country, if not the court, is clear, and that's more important than any Supreme Court decision.