The case being argued on Wednesday, Dobbs v. Jackson Women’s Health Organization, revolves around a 2018 Mississippi law, H.B. 1510, or the Gestational Age Act. The rule bans nearly all abortions after 15 weeks with some exceptions involving medical emergencies and severe fetal abnormalities. There are no exceptions for cases of rape or incest. 

Jackson Women’s Health Organization, the only licensed abortion provider in the state, challenged the law, claiming that it violated precedents set by both Roe v. Wade and Planned Parenthood v. Casey, two landmark cases decades apart that legalized access to abortion. 

The Supreme Court has never before allowed states to ban abortion before 24 weeks, when fetuses are typically able to survive outside the womb. But with a 6-3 conservative majority, pro-choice advocates worry that justices could rule to overturn a critical part of the landmark 1973 case that granted the nationwide right to abortion. 

“This is the most worried I’ve ever been,” Shannon Brewer, who runs the Jackson Women’s Health Organization, told the Associated Press.

If the court overturns Roe and Casey, about 26 states (including Mississippi) would implement complete bans on abortion, according to estimates made by the Guttmacher Institute, a reproductive health and rights research organization. Women in those states would likely have to drive hundreds of miles to reach out-of-state clinics to access abortion care, and the costs and time associated with those drives would likely prohibit many from getting the procedure. 

Roe v. Wade established that during the first trimester of pregnancy, states could not interfere with the decision to have an abortion, and that during the second trimester states could adopt reasonable health regulations but cannot outright ban access to abortions. Nearly two decades later, in Planned Parenthood v. Casey, the Supreme Court reaffirmed that states could not outright ban abortions before fetus viability, which is around 24 weeks. They replaced the trimester guidelines with the “undue burden” test, which allows states to restrict access to abortion at any point in the pregnancy so long as the restrictions do not impose an “undue burden” on a woman’s right to obtain an abortion before a fetus is viable outside the womb. 

Because this Mississippi law violates both of those rulings, it was blocked by a federal district court. The U.S. Court of Appeals for the 5th Circuit, which leans conservative, upheld that ruling. But Mississippi appealed to the Supreme Court, asking the justices to consider the case, and in May, the court agreed to hear the argument. 

In the past, the Supreme Court has denied or ignored such requests. Hearing the oral arguments signals to advocates that the highest court is willing to reconsider the core principle that abortion should be accessible and legal within the U.S., even if they ultimately decide not to rule on it. 

The justices are already separately considering a Texas case that would ban abortion much earlier, at six weeks, and their decision could come as soon as next month. But that case hinges on the way the law is structured and executed, and not on the right to abortion itself.  

The Mississippi case is different in that it attacks previous abortion precedents as “unprincipled decisions that have damaged the democratic process.” It argues that abortion is irrelevant because of available forms of contraception like condoms, that society has shifted to help new mothers to work and support themselves, and that viability is arbitrary because infants are dependent on others to survive even after birth. Those arguments, filed in July, are exceedingly different from the appeal that the Supreme Court first accepted last year, which claimed the 15-week ban wouldn’t require the court to “overturn Roe or Casey.” 

Jackson Women’s Health Organization argues that the court must uphold precedent, and not doing so would be perceived as a political or biased act. It goes on to say that abortion is safer than ever before and that no drastic changes have been made to the process that undermine previous rulings. The clinic has counter-argued that the claim that it is now easier for a woman to prevent unwanted pregnancy and to raise a child while working full-time is  “false and paternalistic.”

If they do rule, the justices are unlikely to reach a decision on the case until much later in their term, which ends in early summer, but their questions during oral arguments this week will likely give a good indication on where they stand.