But those with firmly held beliefs, like Diehl and McKalips, still number in the millions. And they reflect what author Lawrence Tribe has called an enduring "clash of absolutes" that's made Roe v. Wade one of the most contentious Supreme Court rulings ever handed down - one that has had a profound impact on American culture and politics, and, in the eyes of some scholars and activists, could one day be overturned.
Frances Kissling was the director of an abortion clinic in New York City on the day that Roe v. Wade was handed down. She remembers arriving at work at 8 a.m. and "having kids in their dirty cars sitting in the parking lot, having driven from Kentucky and Connecticut and wherever, being afraid, dealing with the fact that they've just come from someplace where abortion was illegal to a place where it was legal."
Then the legal and cultural earthquake struck. In two 7-2 decisions - Roe v. Wade and Doe v. Bolton - abortion was declared a constitutionally protected right, under a right to privacy not explicitly stated in the Constitution, but developed through Supreme Court precedent. Though the justices ruled that states could regulate and ultimately ban abortion as pregnancies progressed, there was no mistaking the fundamental shift.
"It was a shock," says Ms. Kissling, now president of Catholics for Free Choice. "No one expected it."
In his dissent, Justice Byron White castigated the majority for holding that "the Constitution of the United States values the convenience, whim or caprice of the putative mother more than the life or potential life of the fetus."
Justice William Rehnquist decried the trimester system laid out by the majority as "judicial legislation."
At the time, abortion was legal in only four states - New York, Hawaii, Alaska, and Washington. Suddenly, it was legal everywhere. But for abortion-rights forces, the celebration didn't last long. The antiabortion movement, centered at first in the Catholic Church, galvanized and fought abortion on many levels - at the clinics, in state legislatures and courts, in the US Congress, and back in the Supreme Court itself. Abortion-rights forces have played defense ever since.