Since 1973, attitudes toward abortion, as charted by Gallup and the General Social Survey, have held remarkably stable even as the public has become more liberal on other social issues, such as gay rights and women's equality.
"There has been some movement in a prolife direction, but you'd have to get out a magnifying glass" to see it, says Ted Jelen, a political scientist at the University of Nevada at Las Vegas and an author on the subject. "Fifteen percent are prolife, about a quarter to a third are prochoice, and the balance, it depends."
Opinion experts suggest that the effectiveness of the antiabortion movement has bumped up against other trends - such as higher education levels and less affiliation with organized religion - that might otherwise have liberalized opinion toward abortion. When framed around the question of whose choice an abortion decision should be, the public clearly favors the woman. Two-thirds of the public also consistently oppose overturning Roe.
Still, the way abortion is perceived has evolved since 1973. At the time of Roe, discussion centered on the woman's rights. But the rise of technology has altered that.
"All the remarkable developments in fetology and the images we now have of an embryo - how quickly you start to get all those characteristics that we call human, measurable brain activity, and so on - have made it impossible for anyone to make a coherent argument that it's just a blob that isn't human yet," says Jean Bethke Elshtain, a professor at the University of Chicago divinity school. "Clearly, it's a nascent human being. It's not going to be a giraffe."
What makes America's abortion wars so remarkable is how public and political they've been. Part of that speaks to the larger US cultural mosaic - the conflicts of a country that is both deeply religious and committed to secularism, a nation that invented modern feminism but remains ambivalent about women's roles. America's highly legalistic culture has also made it inevitable that a matter as private as reproduction would wind up in the courts.