The court has generally supported the F.D.A.’s authority on drug safety.

In January, South Carolina’s highest court handed down its ruling that the right to privacy in the state Constitution includes a right to abortion, a decision that overturned the state’s six-week abortion ban. On the same day, Idaho’s highest court ruled in the opposite direction, saying that the state’s Constitution did not protect abortion rights; the ban there would stand.

Last month, North Dakota’s supreme court said that its Constitution includes the right to abortion in some cases, though the lawsuit against the state ban will proceed in a lower court.

Those divergent decisions displayed how volatile and patchwork the fight over abortion rights has become, as advocates and opponents of abortion rights push and pull over state constitutions.

For abortion rights groups, state constitutions are a critical part of a strategy to overturn bans that have cut off access to abortion in a wide swath of the country. Those documents provide much longer and more generous enumerations of rights than the United States Constitution, and history is full of examples of state courts using them to lead the way to establish broad rights — as well as to strike down restrictions on abortion. They offer a way around gerrymandered state legislatures that are pushing stricter laws.

The Supreme Court’s decision has left abortion rights groups with few other options. In their most hopeful scenario, state courts and ballot initiatives to establish constitutional protections would establish a firmer guarantee for abortion rights than the one in Roe, which rested on a protection of privacy that was not explicit in the U.S. Constitution.

But just as abortion rights groups are trying to identify protections in state constitutions, anti-abortion groups are trying to amend those same documents, which are easier to change than their federal counterpart, to say they provide no guarantee of abortion rights.

And while the courts may appear to be the last word because their decisions are not subject to appeal, judges in 38 states have to face the voters. A change on the bench has sometimes meant that the same document found to include a right to abortion suddenly is declared not to include that right, in the space of a few years.

“You’re going to see a lot of give and take in the years to come, in ways that may be unpredictable,” said Alicia Bannon, the director of the judiciary program at the Brennan Center for Justice, which with the Center for Reproductive Rights maintains a tracker of the cases filed to challenge abortion bans that have been enacted since the Supreme Court overturned Roe. “I don’t think it’s a dynamic where a court will issue a ruling and that’s the end of the conversation.”

Lawyers working to restore abortion rights promise more litigation as legislatures in conservative states have reconvened over the last three months for the first time since the Supreme Court’s decision, vowing to pass stricter bans. Both sides of the abortion debate will also devote new energy to seat and unseat judges, and into efforts to explicitly protect or restrict abortion protections in state constitutions.