The Supreme Court on Wednesday began to hear historic arguments over a Mississippi law that would ban most abortions after 15 weeks of pregnancy.

       The case, Dobbs v. Jackson Women's Health, asks the justices directly to reconsider the precedent set by Roe v. Wade and Planned Parenthood v. Casey.

       Erin Schaff/Pool/Getty Images, FILE

       Members of the Supreme Court pose for a group photo at the Supreme Court in Washington, D.C, April 23, 2021.

       This means that the justices, a majority of whom are conservative, have the real opportunity to lessen the right to an abortion or possibly overturn the landmark case that made abortion a federally protected right nearly half a century ago.

       Legal scholars are raising the alarm that if the court should decide to uphold the Mississippi ban, it could clear the way for new restrictions on abortion across the U.S.

       MORE: Supreme Court hears historic case on fate of abortion rights

       ABC News legal analyst Kate Shaw, a professor at Cardozo Law School, told ABC News' "Start Here" that as many as 30 states would restrict abortions if Roe gets overturned.

       "It's certainly possible that there will be a majority of justices on board to just overturn Roe and Casey and rule that the Constitution doesn't protect a right to terminate a pregnancy," Shaw said. That would leave each state to decide for itself, and "a number of states already have laws on the books that go into effect immediately."

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       Protesters, demonstrators and activists gather in front of the U.S. Supreme Court as the justices hear arguments in Dobbs v. Jackson Women's Health, a case about a Mississippi law that bans most abortions after 15 weeks, on Dec. 1, 2021 in Washington, D.C.

       According to a report from The Guttmacher Institute, 21 states have these so-called trigger laws, some of which include bans on abortion after six or eight weeks of pregnancy, effectively banning all abortions. Several other states without trigger laws, according to Shaw, would likely "move very quickly" to prohibit abortion should Roe be overturned.

       Erin Schaff/Pool via Getty Images

       Members of the Supreme Court pose for a group photo at the Supreme Court in Washington, D.C., April 23, 2021. Seated from left: Associate Justice Samuel Alito, Associate Justice Clarence Thomas, Chief Justice John Roberts, Associate Justice Stephen Breyer and Associate Justice Sonia Sotomayor. Standing from left: Associate Justice Brett Kavanaugh, Associate Justice Elena Kagan, Associate Justice Neil Gorsuch and Associate Justice Amy Coney Barrett.

       Shaw said she believes that the court could reach a compromise solution that still would allow Mississippi to enforce its 15-week, and even though that also "would be a dramatic change in the constitutional law of abortion, but that they do that without overturning Roe and Casey, simply suggesting that Roe and Casey undervalued the state's interest in protecting potential life, and thus that this viability line should be reconsidered."

       MORE: What would happen to abortion access if Roe v. Wade is overturned or weakened: Report

       Such a ruling could give states more power to restrict abortions, Shaw continued, "but it would not allow them to prohibit or criminalize all abortions."

       This report was featured in the Wednesday, Dec. 1, 2021, episode of "Start Here," ABC News' daily news podcast.

       "Start Here" offers a straightforward look at the day's top stories in 20 minutes. Listen for free every weekday on Apple Podcasts, Google Podcasts, Spotify, the ABC News app or wherever you get your podcasts.