In the years since Roe v. Wade was decided, there were numerous cases trying to specifically delineate what types of regulation of abortion procedures were permissible and which were not. At the same time, reexamination of the reasoning of Roe against strong public reaction was revealing some of the weaknesses of that decision. The conservative bloc on the Court was increasingly pushing to overturn Roe, and Justice Sandra Day O’Connor in particular was very concerned about protecting the former ruling.
The Planned Parenthood v. Casey (1992) case, O’Connor led a plurality of justices to reaffirm Roe’s essential holding of the legality of abortion. However, it also gutted the reasoning behind that decision, throwing out the trimester framework used in Roe and replacing it with a standard that permitted government regulations that did not place “undue burdens” on a woman’s right to choose to abort prior to fetal viability. After viability, the Casey decision reasons that the increased strength of the government interest in potential life even permits the government to largely ban the procedure.