As partisans on both sides of the abortion divide contemplate a Supreme Court with two Trump appointees, one thing is certain: America even without legal abortion would be very different from America before abortion was legal.

The moment Justice Anthony M. Kennedy announced his retirement, speculation swirled that Roe v. Wade, the landmark 1973 ruling that legalized abortion, would be overturned. Most legal experts say that day is years away, if it arrives at all. A more likely scenario, they predict, is that a rightward-shifting court would uphold efforts to restrict abortion, which would encourage some states to further limit access.

Even then, a full-fledged return to an era of back-alley, coat-hanger abortions seems improbable. In the decades since Roe was decided, a burst of scientific innovation has produced more effective, simpler and safer ways to prevent pregnancies and to stop them after conception — advances that have contributed to an abortion rate that has already plunged by half since the 1980s.

“We’re in a new world now,” said Aziza Ahmed, a law professor at Northeastern University who writes about reproductive rights law. “The majority of American women are on some form of contraception. We take it for granted that we can control when and how we want to reproduce. We see pregnancy as within the realm that we can control.”