▶ Watch Video: Legal expert on impact of Supreme Court taking up Mississippi’s 15-week abortion ban Washington — For the first time in nearly 30 years, the future of abortion rights will face its most consequential test when the Supreme Court convenes Wednesday to hear a high-stakes showdown taking aim at nearly five decades of precedent. At the heart of the dispute before the high court, now with a 6-3 conservative majority, is a Mississippi law that bans abortions after 15 weeks of pregnancy. State officials have used the case, known as Dobbs v. Jackson Women’s Health Organization, as a vehicle to ask the justices to overturn Roe v. Wade, the landmark 1973 decision that established a constitutional right to an abortion. Pro-abortion rights advocates warn a decision upholding the 2018 law would pave the way for states to ban the procedure entirely. “There is no middle ground in Dobbs,” said Sherif Girgis, a professor at University of Notre Dame Law School who clerked for Justice Samuel Alito. “It’s very hard for me to see how the court could uphold the 15-week law without entirely eliminating the constitutional entitlement to elective abortion in Roe and Casey.” Under the Supreme Court’s decision in Roe, and reaffirmed in the 1992 case Planned Parenthood v. Casey, states cannot ban abortions before viability — the point at which the fetus can survive outside of the womb, which is now considered to be between 22 and 24 weeks of pregnancy. But Mississippi’s measure outlaws abortions at 15 weeks, before fetal viability, and a key question before the justices in Wednesday’s case is whether to discard the viability line drawn in 1973. “Many are expecting that Dobbs will either be the moment that the Supreme Court overrules Roe or at least will set us on a path to doing so,” said Mary Ziegler, a law professor at Florida State University who has studied the legal history of Roe. “One of the questions that many of us are going to be interested in is whether it’s possible to sever viability from Roe and Casey and have anything left.” Mississippi passed its law, the Gestational Age Act, in 2018. But a federal district court swiftly blocked enforcement of the ban after Jackson Women’s Health Organization, the state’s sole abortion clinic, challenged its constitutionality. The 5th U.S. Circuit Court of Appeals upheld the district court’s ruling, and Mississippi officials asked the Supreme Court to step in last year. Shannon Brewer, director of Jackson Women’s Health Organization, said she is in “disbelief” that the Supreme Court agreed to take the case. Brewer’s clinic serves roughly 3,000 women annually and provides abortion services up to 16 weeks of pregnancy. Roughly 100 patients per year obtain an abortion after 15 weeks, lawyers for the clinic told the high court in a September brief. Jackson Women’s Health Organization is also contending with the impacts of a Texas abortion law, the nation’s most restrictive, that took effect September 1. Since then, Brewer said her clinic has been inundated with calls from women there seeking abortions and estimated one-quarter of daily patients at Jackson Women’s Health are from Texas. The clinic has extended its operations to five to six days per week, and doctors are flying in to help with the influx of patients, she said. The Texas measure prohibits abortions after embryonic cardiac activity is detected, usually at about six weeks and before many women know they’re pregnant. The Supreme Court is separately weighing a pair of cases involving the Texas ban, which focus on its design and who can challenge the law in federal court. The Supreme Court’s decision to hear the Mississippi abortion case marks a watershed in a decades-long push by anti-abortion advocates to overturn Roe. Those efforts were buoyed by former President Donald Trump’s reshaping of the high court through his appointments of Justices Neil Gorsuch, Brett Kavanaugh and Amy Coney Barrett, which expanded its conservative majority to 6-3. Mr. Trump pledged to name “pro-life justices” who would overrule the Supreme Court’s abortion decisions. “We’re hopeful that this case is going to spell out the end of Roe v. Wade, and somebody has to be speaking up for these children, especially for the unborn. They’re innocent lives,” Governor Kristi Noem, Republican governor of South Dakota, said during a virtual press conference hosted by Susan B. Anthony List. While the Supreme Court could uphold the Mississippi law without scraping Roe and Casey, lawyers for Jackson Women’s Health Organization warn such a decision would still amount to overturning its landmark abortion rulings by abandoning the viability line, effectively inviting states to ban abortions outright. A dozen states including Mississippi have already passed so-called “trigger bans,” in which most abortions would be outlawed if and when the Supreme Court overturns Roe. The Guttmacher Institute, an abortion rights research organization, estimates that if Roe is overturned or weakened, at least 21 states are poised to attempt to ban abortion. “A decision upholding this ban is tantamount to overruling Roe,” said Julie Rikelman, a lawyer for the Center for Reproductive Rights who will argue against the ban Wednesday, noting the Mississippi law prohibits abortion about two months before viability. “There’s just no way that is constitutional under the right recognized in Casey and Roe.” Mississippi officials, however, argue abortion policy is best addressed by the states, not the courts, and told the Supreme Court that Roe and Casey are “unprincipled decisions that have damaged the democratic process, poisoned our national discourse, plagued the law — and, in doing so, harmed this court.” The state argued that at a minimum, the court should reject the viability line. But officials also put forth two other options for the Supreme Court to pursue: Uphold Mississippi’s ban and leave unanswered the question of what standard to apply in the absence of a viability rule, or clarify the undue-burden standard set out in the 1992 Casey decision and allow a state to prohibit abortions before viability “if it does not impose a substantial obstacle to ‘a significant number of women’ seeking abortions.” “Roe and Casey are egregiously wrong,” Mississippi officials told the high court in a brief. “The conclusion that abortion is a constitutional right has no basis in text, structure, history, or tradition.” A decision from the Supreme Court is expected by summer 2022.