The Supreme Court Takes Up Gay Marriage: It Can Make History - or Punt Chip Somodevilla / Getty Images Same-sex marriage proponent Kat McGuckin of Oaklyn, N.J., holds a gay pride flag while standing in front of the Supreme Court in Washington, Nov. 30, 2012. The U.S. Supreme Court's announcement that it will hear two cases involving gay marriage in March is a milestone in one of the fastest-moving civil rights campaigns in American history. With the nine justices almost certainly locked into a 5-to-4 split, and with no certainly where the decisive vote will fall, the moment holds equal parts peril and promise for advocates on both sides of the fight over whether same-sex couples can legally be married. But while the stakes are sky high, Friday's orders from the court do not guarantee that the decisions, expected as soon as June, will offer anything like the final word on gay marriage in America. PHOTOS: Early Days in the Fight for Gay Rights In fact, in order to address the question of marriage at all, both cases will first have to survive scrutiny by the justices on a far more mundane question: Do the appealing parties have standing to bring the cases at all? In agreeing to set the cases for oral arguments in March, the justices on Friday ordered attorneys in both cases to brief the question of standing, a clear signal that the court is reserving the option of punting on the cases instead of addressing the broader constitutional questions related to gay marriage. What is standing? It's a legal concept that comes from the constitution's requirement that only cases that involve real injuries to specific parties be heard in the federal courts. That means, for instance, that you can't sue a drunk driver for injuries because you think he might crash into your house on the way home from the bar. And you can't sue him because he ran over your neighbor, either. The neighbor-or her estate-would have to do that. If both cases the Court has decided to hear are thrown out on jurisdictional grounds - that is because of a lack of standing-the lower court rulings will be upheld. That will mean victories for gay rights advocates, but likely in far narrower ways than advocates have hoped for. In the California case, lower courts have twice ruled that a 2008 ballot initiative (the so-called Prop 8) that changed the constitution to ban gay marriage violated the federal constitution. The district judge ruled in sweeping terms, finding that the right to gay marriage was guaranteed by the U.S. Constitution. The state of California declined to appeal that ruling, which would have ordinarily meant that the decision would stand. But instead, the group that had led the petition drive to put the question on the ballot in the first place asked for permission to appeal in the state's place, a request that was eventually granted. When the liberal-leaning Ninth Circuit finally ruled on the case, it did so on far less grand terms than since-retired Chief District Judge Vaughn Walker. Instead of finding a fundamental right to marry in the constitution, the Ninth Circuit said merely that California voters had gone too far when they amended their state constitution to take away a right that had already been granted - a set of factors that would only be meaningful for California. That narrower decision is on appeal before Supreme Court now, not the broader ruling by Walker. But if the Supreme Court chooses to rule that the petitioners never had standing to appeal in the first place, it will be Walker's decision that becomes law. That would be a sublime victory for gay rights in California, where some 18,000 couples were married before Prop 8 took effect. But by deciding the case on the question of standing the Supreme Court would have avoided having to decide the question of gay marriage for the rest of the country. Walker's decision would only be meaningful in the Golden State. The second case being teed up for a Supreme Court decision comes out of New York and involves standing in a different way. Several lower court judges have ruled that the 1996 Defense of Marriage Act (DOMA) is unconstitutional, essentially because it forbids the U.S. Government from recognizing valid state marriages between same-sex spouses, a law that means for tax or employment purposes, for instance, gay couples legally married in New York are deemed to be single by the federal government. The Supreme Court has agreed to hear an appeal of those lower court decisions. But because President Obama has ordered his justice department not to defend DOMA in courts, it has fallen to the U.S. House of Representatives to retain lawyers to defend the statute. Before they decide whether the lower courts have been right, the justices said Friday that they want to hear arguments about whether the House leadership has standing to defend a law the President has determined to be unconstitutional and won't defend. In the New York case, called Windsor v. United States, a ruling that the appeal lacks standing would leave intact the Second Circuit's ruling striking down the Clinton-era DOMA. But because that ruling is only binding in the Second Circuit, the Supreme Court could avoid weighing in altogether on the more central question - whether DOMA's restrictions on gay couples pass constitutional muster. The law would remain in effect for the rest of the country. Noted constitutional legal scholar Erwin Chemerinsky told TIME on Friday that the standing issue is a critical one in these cases, and said the court wasn't simply looking for a way out of deciding the cases on the merits. "I think these are really hard standing questions," says the dean of the University of California at Irvine law school and a supporter of gay marriage. If the government chooses not to defend a law, who, if anyone, may do so? A court can decide an issue only if it has jurisdiction. He told TIME: "I think the Court was right to take up the jurisdictional questions. I think there is a real possibility the cases could be dismissed on jurisdictional grounds. Still, legal observers and advocates alike were eager to point out that just because the Supreme Court has given itself room to punt on the broader legal questions in these cases doesn't mean they won't find the votes for a more expansive ruling. Opponents of gay marriage hailed Friday's announcements as indications that the Supreme Court is finally weighing in to stop the steady assault on traditional definitions of marriage underway in state and federal courts. "We believe that it is significant that the Supreme Court has taken the Prop 8 case," said John Eastman, chairman of the National Organization for Marriage, and former dean at Chapman University School of Law, in a statement Friday. We believe it is a strong signal that the Court will reverse the lower courts and uphold Proposition 8. That is the right outcome based on the law and based on the principle that voters hold the ultimate power over basic policy judgments and their decisions are entitled to respect. Eastman added, "Had the Supreme Court agreed with the lower courts" decisions invalidating Proposition 8, it could simply have declined to grant certiorari in the case." Despite his speculation about the possibility of decisions based on standing, Chemerinsky says the fact that the justices agreed to take both cases at the same time is likely to mean they are preparing for a broader ruling-assuming they can get past any jurisdictional concerns. "I think the Court taking both means it is likely that the Court will rule more broadly on whether there is a right to marriage equality for gays and lesbians," he told TIME. Had the Court only taken Windsor, about the constitutionality of the Defense of Marriage Act, it could have limited its decision to what the federal government can do. Now, I think the Court will take the more general question: Do gays and lesbians have the right to marry? If the justices do address the larger questions of whether gays have the right to marry, the decision is expected to come down to Justice Anthony M. Kennedy, a conservative judge who has, nevertheless, played a key role in deciding previous cases in favor of gay rights. And in that way, Chemerinsky suggested, the same steady drumbeat toward gay rights that Eastman so hopes the Supreme Court will finally halt could be the deciding factor in creating a majority to uphold gay marriage. "I think Justice Kennedy wants to be on the right side of history," he told TIME. There's no doubt where history is going on this. The November elections saw three states approve gay marriage initiatives and one reject an initiative to ban it. ... Kennedy wants to write the next Brown v. Board of Education. VIDEO: Going to the (Pop-Up) Chapel and We're Gonna Get (Same-Sex) Married Michael A. Lindenberger is a contributor to TIME.com and currently a John S. Knight journalism fellow at Stanford University.