WASHINGTON (AP) — The Supreme Court agreed on Monday to decide a major abortion case that could dramatically alter decades of rulings on abortion rights and eventually lead to dramatic restrictions on abortion access.

It's been nearly 50 years since the court announced in its landmark 1973 Roe v. Wade decision that women have a constitutional right to abortion.

Here are some questions and answers about the case:

COULD THIS BE THE CASE THAT OVERTURNS ROE V. WADE?

The case is an appeal from Mississippi in which the state is asking to be allowed to ban most abortions at the 15th week of pregnancy. The state is not asking the court to overrule Roe v. Wade, or later cases that reaffirmed it.

But many supporters of abortion rights are alarmed and many opponents of abortion are elated that the justices could undermine their earlier abortion rulings. If the court upholds Mississippi's law, it would be its first ratification of an abortion ban before the point of viability, when a fetus can survive outside the womb. Such a ruling could lay the groundwork for allowing even more restrictions on abortion. That includes state bans on abortion once a fetal heartbeat is detected, as early as six weeks.

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WHAT HAPPENS IF MISSISSIPPI WINS?

If Mississippi wins, it gets to enforce its 15-week ban, which lower courts have so far prohibited. In addition, other conservative states would certainly look to copy Mississippi's law. A decision that states can limit previability abortions would also embolden states to pass more restrictions, which some states have already done and which are already wrapped up in legal challenges. Challenges to those limits would continue.

That said, the immediate practical impact of a win for Mississippi could be muted. That's because more than 90% of abortions take place in the first 13 weeks of pregnancy, according to the U.S. Centers for Disease Control and Prevention.

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THE COURT IS CONSERVATIVE. IS THERE A LIKELY OUTCOME?

Mississippi would seem to have the upper hand, both because the justices agreed to hear the case in the first place and because of the makeup of the court. After the death of liberal Justice Ruth Bader Ginsburg in September and her replacement by conservative Justice Amy Coney Barrett, conservatives hold six of the court's nine seats.

Barrett, one of former President Donald Trump's three appointees to the court, is the most open opponent of abortion rights to join the court in decades. Trump's other two appointees, Justices Neil Gorsuch and Brett Kavanaugh, voted in dissent last year to allow Louisiana to enforce restrictions on doctors that could have closed two of the state’s three abortion clinics.

Justice Samuel Alito would also be expected to be a vote for Mississippi, while Justice Clarence Thomas is on record in support of overturning Roe v. Wade.

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WHEN WILL THE PUBLIC KNOW WHAT THE COURT DOES?

The court has finished its calendar of scheduled oral arguments for now and is issuing decisions before taking a break for the summer. The court will resume hearing arguments in October, and this case will probably be argued in the fall. A decision would likely come in the spring of 2022 during the campaign for congressional midterm elections.

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WHERE ARE AMERICANS ON THE ISSUE OF ABORTION?

An April poll from the Pew Research Center found that 59% of Americans think abortion should be legal in most or all cases, while 39% think it should be illegal in most or all cases. Eighty percent of Democrats said abortion should be legal in all or most cases, compared with just 35% of Republicans.