Justices in the Supreme Court’s six-member conservative majority on Wednesday raised substantial doubts about the jurisprudence behind the 1973 case establishing abortion rights in the United States, Roe v. Wade, during arguments over a Mississippi law banning abortions after 15 weeks’ gestation.

Dobbs v. Jackson Women’s Health Organization, combined with arguments on Nov. 1 over a Texas anti-abortion law, represents the most direct challenge in decades to Roe, which made abortion a national right rather than letting states decide the issue. The rulings, which will be issued by June 2022, have the potential to sway politics substantially, with the underlying issue a motivating one at the ballot box for opponents of abortion and supporters of abortion rights.