Today, the United States Supreme Court will hear oral arguments on Proposition 8. It’s a moment the legal civil rights community had avoided for years, fearing the risks involved – and choosing more incremental approaches, like challenging the Defense of Marriage Act (the Court will hear oral arguments on DOMA tomorrow.) But once the Prop 8 trial went underway in January 2010, a sense of optimism grew that things would go our way. And with four states voting to affirm marriage rights for same-sex couples last November, followed by a cascade of elected officials in recent weeks coming out in support, we all know that it’s only a matter of time. For our conservative opponents, they have known since Day One of the Trial that their saving grace would be five Justices on the Supreme Court – which remains a possibility. After the Court hears arguments today, they will deliberate and issue a decision in June. The following are five possible ways they could rule …

Option 1: Deny Standing to Prop 8 Supporters

One reason why this case took so long to get to the U.S. Supreme Court (more than 4 years after Prop 8 passed, and more than 2 years after the Trial commenced) was that the Ninth Circuit Court of Appeals spent much of 2011 reviewing the question of standing. Because California Governor Jerry Brown and Attorney General Kamala Harris have refused to defend Prop 8, the question came down to whether its right-wing proponents had “standing” to appeal Judge Vaughn Walker’s decision.

A litigant must have suffered an “injury” to have standing, and Prop 8 proponents have failed to articulate why they – as private right-wing citizens, rather than the government – would be harmed by letting same-sex couples marry. The Supreme Court could rule they don’t have standing, which would allow Judge Walker’s original decision to hold. Prop 8 would be overturned and gay couples could marry, but the decision would have no effect beyond California – and there would be no legal precedent on the question of whether such anti-gay measures are unconstitutional.

But I don’t expect the Supreme Court to rule that way for several reasons. First, the question was exhaustively litigated – the Ninth Circuit even punted it back to the California Supreme Court, who ruled that Prop 8 supporters had standing. Because Prop 8 was a “citizen initiative,” it can be argued the drafters step into the shoes of elected officials – and “represent” the state for this limited purpose.

In a sign that it’s not likely to be found, the U.S. Supreme Court has set aside time for “standing” on DOMA oral arguments tomorrow – where the Obama Administration has likewise refused to defend an anti-gay law, and right-wing proponents have had to step in to “represent” the federal government. But the Court has not done the same for Prop 8, which suggests that they want to go to the merits of the question.

Regardless of the outcome, Prop 8 will likely be decided on the merits.

Option 2: Uphold Prop 8, Reversing the Lower Courts

The Supreme Court could uphold Prop 8, depriving same-sex couples of the right to marry and forcing advocates in California to repeal it at the ballot box. This is the outcome the civil rights community has dreaded for years – that filing a lawsuit in federal court was “too risky,” “too soon” and could set back the LGBT community.

Right-wing proponents of Prop 8 have counted on a 5-4 win at the Supreme Court all along. Back in January 2010, on the first day of trial Brian Brown of the anti-gay National Organization for Marriage wrote in an e-mail: “We do not expect to win at the trial level. But with God’s help, at least five members of the current Supreme Court will have the courage to defend our Constitution from this grave attack.”

But a lot has changed since 2010. A solid majority of Americans now support the freedom to marry (especially in California), and last November three states – Maine, Maryland & Washington – voted to grant marriage for same-sex couples, and in Minnesota voters defeated an anti-gay amendment. The latter is significant, because until then opponents could argue that “the people” had always voted on their side.

While the Supreme Court doesn’t want to be seen as “judicial activists,” they also don’t want to be on the wrong side of history. And Chief Justice John Roberts, in particular, is leery of the Court’s right-wing image. Some have even speculated this was why he voted to uphold Obamacare – so the Court’s conservative majority would have the political space to wreak havoc on more low-profile cases. Throw liberals a victory on Prop 8, and it distracts the public from their other Supreme Court cases.

I predict the Court will repeal Prop 8, although my opinion may change after hearing today’s oral arguments. Even so, there are three possible ways the Court could rule that would overrule Prop 8 – and grant marriage rights for California gay couples.

Option 3: Repeal Prop 8, But Only for California

The Court could uphold the Ninth Circuit decision – which repealed Prop 8 on narrow grounds. Unlike other anti-gay marriage amendments passed in 32 other states, Prop 8 was unique because it affirmatively took away the right from same-sex couples – after they had it for six months. There was no basis except “animus” – which the Court in Romer v. Evans (1996) concluded was not rational, after a Colorado initiative repealed all anti-gay nondiscrimination laws.

Justice Anthony Kennedy – the “swing” vote – wrote the Court opinion in Romer v. Evans, and the Ninth Circuit decision was clearly written with him in mind. It would not force Kennedy to do anything besides repeat what he said in Romer, and would allow the Court to repeal Prop 8 – but in such a way that it could only apply to California. It would not require them to answer the question of whether anti-gay discrimination requires a higher level of scrutiny, such as race or gender.

One year ago, a narrow Supreme Court opinion that only applies to California was the best we could hope for. But the political landscape on this issue has changed dramatically, which suggests that the Court could go further. Marriage equality supporters – from the Prop 8 plaintiffs to President Obama – will be arguing for a broader ruling, which could lead to one of the following two outcomes.

Option 4: Repeal Prop 8 via the Nine-State Solution

In its amicus brief supporting the Plaintiffs, the Obama Justice Department argued that Prop 8 should be repealed – because for a state to grant civil unions, but not marriage, for gay couples violates equal protection. In today’s oral arguments, Solicitor General Theodore Boutros will get time to argue this point.

If the Court overrules Prop 8 on these grounds, it will apply to California and eight other states – Colorado, Delaware, Hawaii, Illinois, Nevada, New Jersey, Oregon and Rhode Island. There is no compelling reason or rational basis to determine that gay couples should have all the legal benefits of a domestic partnership – but to then deny them marriage. In five of these states – Delaware, Illinois, Rhode Island, New Jersey & Hawaii – efforts are underway to pass a marriage bill in the legislature, and could pass later this year. In Oregon, which passed a similar amendment to Prop 8 in 2004, advocates are collecting signature to repeal the ban in November 2014.

Supreme Court Justices are leery of being “too far” ahead of the people. Even Ruth Bader Ginsburg recently said that – while Roe v. Wade was a right decision, politically it engendered a backlash and that perhaps the Court should have waited. But a ruling on these grounds is not too ambitious. After all, a majority of voters in these states generally support same-sex marriage – and in some cases, a legislative solution is imminent. The Supreme Court would simply be doing the inevitable.

Option 5: Grant Marriage Equality to All 50 States

While the Justice Department will argue the more incremental “Nine-State Solution,” lawyers Ted Olson and David Boies will argue that the Supreme Court should grant marriage to same-sex couples as a Constitutional right. Marriage is a fundamental right – and just like the Court in 1967 found it unconstitutional to deny marriage for interracial couples, the same can be said to gay couples today. This would apply the same ruling that Trial Court Judge Vaughn Walker originally made for this case.

Such a ruling would have the same broad historic sweep that Roe v. Wade had for abortion rights, and Brown v. Board of Education did for the civil rights movement. Which is why most observers (including myself) doubt that the U.S. Supreme Court, with its inherently conservative inclinations, would go that far. We are on the right side of history, but the Court may fear a political backlash if a Prop 8 decision would apply to states like Texas, Alaska, Oklahoma or Mississippi.

But in last Sunday’s New York Times, columnist Frank Bruni made a compelling argument as to why such a ruling would not result in the kind of reaction we have seen with Roe and other such cases.

“The abortion debate grinds on in part because to those who believe that life begins at conception and warrants full protection from then on, every pro-choice victory claims victims,” writes Bruni. “But the legalization of same-sex marriage takes nothing from anyone, other than the illusion – which is all it is and ever was – that healthy, nurturing relationships are reserved for people of opposite sexes.”

Which brings us back to the standing question. Despite having strong political and religious feelings about the issue, how are opponents “harmed” by same-sex couples getting married – and having their relationship recognized by the law? If the Court applied the best legal arguments, Prop 8 would be overruled on the standing issue alone. But the Courts don’t always follow the best arguments – after all, the Justices are just well-connected lawyers with robes, who are influenced by political factors.

Which is why we can hope that the Supreme Court goes with Option #5 – and grants marriage equality to all 50 states. But no one should really expect them to …

Stay Tuned Tomorrow, as Paul Hogarth analyzes the Prop 8 Oral Arguments – and offers a preview of the Supreme Court’s oral arguments on DOMA. On March 28th, the San Francisco LGBT Community Center will host a re-cap of the oral arguments with attorneys from the ACLU and the National Center for Lesbian Rights from 6:00 to 8:00 p.m..

Paul Hogarth has a J.D. from Golden Gate University Law School, and is licensed to practice law in California. He was a legal intern at Equality California in the summer of 2005, was active in Bloggers Against Prop 8, organized volunteers in 2009 who traveled to Maine for the marriage campaign, live-blogged the Prop 8 trial for the Courage Campaign in January 2010 and in 2012 worked as a Campaign Consultant for United for Marriage – a project that sent volunteers to Maine, Maryland, Minnesota & Washington to supplement campaign field efforts. Follow him on Twitter at @paulhogarth.