The difference was the composition of the court. Chief Justice William Rehnquist was replaced by Chief Justice John Roberts and Justice Sandra Day O'Connor was replaced by Justice Samuel Alito. Alito's vote gave the majority the five votes needed to uphold the ban.
Kathryn Kolbert of Barnard College, who is a veteran of the abortion wars, argued and won in 1992 the case Pennsylvania v. Casey, which upheld the core holding of Roe. She, too, is watching the progress of the Nebraska bill.
"I spent my career following these types of bills, thinking about legislative strategy that would impact … making all kinds of strategic decisions," she said. "I was probably in 44 states in the years leading up to Casey."
Kolbert looks at the Supreme Court today and is worried about the strong conservative block. She is particularly worried that Justice Anthony Kennedy, who voted to uphold Roe, might be slipping to the conservative side of the issue.
"Kennedy was with us on Casey, but O'Connor's presence on the court was central to Kennedy, Kolbert said. "He has shifted since O'Connor left the bench."
She pointed to language Kennedy wrote in the Gonzales decision that she believes suggests that women are somehow incapable of understanding the magnitude of the decision: "Whether to have an abortion requires a difficult and painful moral decision," Kennedy wrote, "which some women come to regret."
Kolbert said, "I don't think O'Connor would have let him get away with that. It feeds into a stereotype that women are too emotional, they don't know what they are doing."
But some conservatives believe that science is evolving, suggesting that the court may revisit precedent.
"Since 1973, there has been a lot of development in what we know about the developing, unknown child," Balch of the National Right to Life Committee said. "This new information should make it to the Supreme Court."