WATCH: U.S. Supreme Court seems poised to restrict abortion access after dramatic oral arguments

WASHINGTON, DC — Members of the U.S. Supreme Court’s conservative majority are suggesting they may make sweeping changes to limit abortion rights in the United States.

The high court heard arguments Wednesday in which the justices were asked to overturn the court’s historic 1973 Roe v. Wade decision legalizing abortion and its 1992 ruling in Planned Parenthood v. Casey, which reaffirmed Roe.

The case in point Wednesday involved a Mississippi law that would limit abortions to women who are 15 weeks or less pregnant. But Mississippi is also asking that Roe v. Wade be thrown out and conservative justices expressed skepticism about the landmark decision.

The dispute represents the culmination of a decades-long effort on the part of critics of the landmark opinion that legalized abortion nationwide to return the issue to the states, a move that would almost immediately eviscerate abortion rights in large swaths of the South and the Midwest.

Chief Justice John Roberts seemed to be looking for a middle ground to allow states to ban abortion earlier -- moving up the viability line from the current 22 to 23 weeks -- but leaving in place some remnants of a woman's right to end an abortion. He said 15 weeks was not a "dramatic departure" from viability.

Another key justice, Brett Kavanaugh, however, noted that even if the issue were returned to the states, abortion would still be available in some of those states. He conceded that supporters of abortion rights have a "forceful argument" but asked if there were two interests at stake, why the court should be the arbiter.

The court's other four conservatives were clearly critical of 1973's Roe v. Wade and 1992's Planned Parenthood v. Casey, which enshrined the right to abortions nationwide. Sixty percent of Americans say Roe should be upheld, according to an ABC News/Washington Post poll conducted in November.

The very fact that the current court, with its solid six-member conservative majority, agreed to even consider a state law that bars abortion long before viability suggests that the court -- bolstered by three of former President Donald Trump's appointees -- is poised to scale back court precedent if not reverse it outright. Already, in a separate dispute, the court is considering a Texas law that bars the procedure after six weeks and the justices have allowed that law to remain in place for three months, rendering Roe a dead letter in the country's second largest state.

Mississippi's Gestational Age Act, passed in 2018 but blocked by two federal courts, allows abortion after 15 weeks "only in medical emergencies or for severe fetal abnormality" and has no exception for rape or incest. If doctors perform abortions outside the parameters of the law, they will have their medical licenses suspended or revoked and may be subject to additional penalties and fines.

Mississippi Solicitor General Scott Stewart was blunt in his opening.

"Roe vs. Wade and Planned Parenthood versus Casey haunt our country," Stewart said. "They have no basis in the Constitution. They have no home in our history or traditions. They've damaged the democratic process. They poison the law. They've choked off compromise. For 50 years they've kept this court at the center of a political battle that it can never resolve and 50 years on, they stand alone. Nowhere else does this court recognize a right to end a human life."

Arguing for the Biden administration in support of the clinics, Solicitor General Elizabeth Prelogar urged the justices to uphold precedent and avoid a ruling that would disproportionally harm women who have come to depend upon the decision.

"For a half century, this Court has correctly recognized that the Constitution protects a woman's fundamental right to decide whether to end a pregnancy before viability," she argued. "That guarantee, that the state cannot force a woman to carry a pregnancy to term and give birth, has engendered substantial individual and societal reliance. The real-world effects of overruling Roe and Casey would be severe and swift."

She added: "The court has never revoked a right that is so fundamental to so many Americans and so central to their ability to participate fully and equally in society.

Lawyers for Jackson Women's Health Organization, the only licensed abortion clinic in Mississippi, and Sacheen Carr-Ellis, the clinic's medical director, told the justices there is no way to sustain the controversial law without effectively overturning Roe. They urged the court to "reject the invitation to jettison a half-century of settled precedent."

"Accepting Mississippi's request to abandon the viability line would turn back the clock for generations who have never known what it means to be without the fundamental right to make the decision whether to continue a pregnancy," Julie Rikelman, the senior litigation director for the Center for Reproductive Rights who is representing the clinic, argued in court papers.

The case comes as states hostile to Roe across the country are moving aggressively to pass abortion restrictions.

"Over 100 restrictions passed this year," said Nancy Northup, president of the Center for Reproductive Rights, said in a conference call with reporters before the arguments.

She noted that 54,000 to 63,000 people get abortions after 15 weeks every year in the US and that if Roe were overturned, nearly half the states would ban abortion entirely. Twelve states have so called "trigger" laws in place designed to ban abortion immediately. Nine more have pre-Roe bans on the books and the rest have legislatures historically hostile to Roe.

A district court had blocked the Mississippi law, holding that it is in direct violation of Supreme Court precedent legalizing abortion nationwide prior to viability, which can occur at around 23-24 weeks of pregnancy.

A panel of judges on the 5th US Circuit Court of Appeals agreed with the district court holding that in an "unbroken line dating to Roe v. Wade, the Supreme Court's abortion cases have established (and affirmed and re-affirmed) a woman's right to choose an abortion before viability." The court said states may "regulate abortion procedures prior to viability" so long as they do not ban abortion. "The law at issue is a ban," the court held.

Mississippi appealed the decision to the Supreme Court, and after the justices agreed to hear the case, the state raised the stakes and argued that the justices should not only uphold the law but also invalidate Roe and Casey.