In the 1999 case of Stenberg v. Carhart, the U.S Supreme Court ruled that a Nebraska law banning partial-birth abortions was unconstitutional. The court held in a 5-4 decision that the law violated a woman's constitutional right to have an abortion before viability as established by Roe v. Wade and reaffirmed by Planned Parenthood v. Casey because it lacked an exception for preserving the health of pregnant women and imposed an undue burden on their ability to choose this procedure over others which may not be safe or effective for them. Furthermore, it found that the language used in defining "partial birth abortion" was too vague, potentially criminalizing other common methods of second-trimester abortions thereby chilling physicians from performing any such procedures out of fear they might face prosecution, civil suits or professional disciplinary action.

In the dissenting opinion for Stenberg v. Carhart, Justice Scalia argued that the Nebraska law banning partial-birth abortions did not impose an undue burden on a woman's right to have an abortion and should therefore be upheld. He criticized the majority for its interpretation of Planned Parenthood v. Casey, stating that it was incorrect to assume any regulation creating a substantial obstacle to obtaining an abortion is unconstitutional. Furthermore, he disagreed with their assessment of medical uncertainty surrounding the procedure; in his view, if there were disagreement among reputable medical experts about whether this particular method posed significant health risks compared to other methods available after viability (the point at which fetuses can survive outside womb), then it was within state’s prerogative to ban it until further evidence emerged one way or another.