The Supreme Court has its hands full, as it ponders whether to take up LGBT rights cases from around the country, including California's on-again, off-again Proposition 8.

On Friday, the justices will enter conference, where they meet in private to look at questions from lower courts and decide if they want to rule on them.

Four of nine justices must agree to take a specific case, and they can decide to take one, some, or all of them. (This is called granting certiorari.)

The court will look at up to five cases that relate to the federal Defense of Marriage Act (DOMA), the best known of which is California's Proposition 8. Section 3 of DOMA, passed in 1996, denies federal benefits to same-sex partners, even if those couples live in a state with marriage equality. Prop 8 is similar to DOMA, in that it denies benefits to same-sex partners of state employees.

A number of outcomes are possible, some more significant than others, and depending on how the justices choose which cases to look at, and how they rule, there could be a significant shift in federal policy in the coming months.

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Public opinion about gay marriage is turning, and quickly. As it stands, the majority of Americans (51 percent) approve of marriage equality, and after the huge successes earlier this month in Maine, Minnesota, Washington, and Maryland, bringing the count to nine states and DC that allow same-sex marriage, the court may consider that change in those states means thousands more couples affected by DOMA.

"The number of couples who are married at the state level who will not be recognized because of DOMA will get bigger and bigger, so the scope of the problem will grow. That might influence the question of whether to resolve the issue," said Brian Moulton, legal director of Human Rights Campaign, to the Guardian. "The justices are people as well and they read the newspapers. That gives them a sense of where the country is going on these issues."

To make the whole situation even more exciting (as if it wasn't confusing enough), there could be a wild card scenario where Justice Kagan recuses herself from ruling on DOMA because of a conflict of interest.

As Solicitor General in the Obama Justice Department, Kagan was involved in deciding how the administration would defend DOMA, a federal law. President Obama instructed the DOJ to cease defending DOMA in 2011, likely with Kagan's influence.

"[Kagan's recusal] would be a blow to having the Supreme Court hear one of the challenges," said Los Angeles attorney Roberta Bennett. "We have what I consider to be a pretty equally divided Supreme Court right now, meaning four conservative justices and four liberals, Kagan being one of the liberals. The swing vote is often Kennedy, but if Kagan is not there, then you have to pick up Kennedy and one other conservative."

DOMA's Section 3, which the Obama administration has backed away from, defines a "spouse" as "a person of the opposite sex who is a husband or a wife," and effectively bars same-sex spouses from receiving the thousand-plus federal benefits afforded to heterosexual spouses.

Should the court decide to rule on one of the DOMA challenges, they only need to choose one of the cases, not all five, to declare Section 3 unconstitutional, which is the whole shebang to hundreds of thousands of same-sex couples across the country hoping the Supreme Court will rule in their favor.

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However, even if the justices do declare one part of DOMA unconstitutional, it doesn't necessarily mean the sweeping changes many are hoping for. It won't immediately make same-sex marriage legal in America.

"Even though the federal law is supposed to be the supreme law of the United States, there are some areas of the law that are accorded just to the states – marriage happens to be one of those," said Bennett. "Whether this will have anything to do with Section 2 [which maintains the states' right to decide what the marriage laws are] is hard to say."

But because it has been ruled to be unconstitutional in five lower courts, there is a strong case for overturning Section 3, regardless of the other part DOMA.

However, Proposition 8 is another story.

Because the case now only refers to California law and whether rights can be taken away once they are already granted, not same-sex marriage specifically, many believe the Supreme Court will choose not to rule on Prop 8, deny certiorari, and stay the 9th Circuit's decision to overturn it.

"I think the reason they will not take the Prop 8 case is because it's a very narrow issue," said Bennett, an award-winning lawyer who has been practicing LGBT family law since 1979. "The Prop 8 case is not a referendum on if there should be gay and lesbian and same-sex couple marriages. There's a different slant."

Even the lawyers representing the defendants in the Prop 8 case aren't sure if they want the Supreme Court to rule on it.

Ted Olson, a conservative attorney who served as Solicitor General under George W. Bush and was part of the Romney campaign's debate prep team, has been the legal force behind the push against Prop 8. As far as he's concerned, although it could possibly lead to something larger, they've already won the case and the Supreme Court could stand down.

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"We won the case, and if they don't take it, our clients have won. They will be allowed to marry," Olson said to the Los Angeles Times this week. "But if they take the case, it could lead to a broader victory. We believe gays and lesbians have a constitutional right to be treated equally. And if it is a constitutional right, you shouldn't have to try to win at the ballot box in every state."

Justice Kennedy is also a question mark on marriage equality questions. Though he's ruled in favor of marriage equality twice, there's no telling where he'll land on these cases, should the justices decide to rule on them, or if he would break with conservatives to tie it up.

No matter the outcome on Friday, the country faces a marriage equality a toss-up that puts the whole question in jeopardy, especially if Justice Kagan recuses herself.

If the Supremes decide not to rule on these cases, they will stand at the state and federal circuit levels, and relegated to being specific to those states and courts, and will not have national implications.

In California, if the justices decide to deny certiorari, same-sex marriage becomes definitvely legal once and for all.

For more of GlobalPost's coverage of the marriage equality debate at home and abroad, check out our Special Report "The Rainbow Struggle: A Global Battle over Gay Rights."