Why do poll numbers matter if the final word still rests with the United States Supreme Court? Because those justices are far more attached to political realities than they might admit. In fact, Roe v. Wade is still the law of the land because of the pull of public opinion on the Supreme Court. In the 1992 case Planned Parenthood v. Casey, Justice Sandra Day O’Connor upheld Roe, in part, because O’Connor perceived that upholding the law was still supported by public opinion. To overturn it, O’Connor wrote, might undermine public confidence in the court.

Two decades later, opinions on abortion have moved rightward because of advances in science and technology. Viability has been pushed forward since Roe was handed down 40 years ago, and 3D imaging now connects parents to their unborn children in ways not imagined in 1973.

Five years ago, I spent much of my summer in the NICU of Sacred Heart Hospital in Pensacola, Fla., with my youngest son who had been born 10 weeks early. There were other babies in the NICU ward who had been born much earlier. The remarkable advances made over the past 40 years in this area have moved viability forward. And because of the medical complications surrounding Jack’s birth, we saw detailed imaging of him early in the second trimester that revealed physical traits that I recognize today as my 5-year-old boy runs around the backyard playing tag with his sister.