In the case of Williams et al. v. Zbaraz et al., 1979, the U.S Supreme Court was tasked with deciding whether Illinois' Public Aid Code violated the Constitution by providing public funding for abortions necessary to preserve a woman's life but not those performed for other medical reasons or due to rape and incest. The court ruled in favor of Zbaraz, upholding that states are not required to fund all types of medically necessary abortions if they choose to subsidize maternity care expenses. This decision upheld an earlier ruling (Maher v Roe) which stated that while women have a constitutional right to choose abortion under certain circumstances, states are not obligated financially support their choice.

In the dissenting opinion for Williams et al. v. Zbaraz et al., Justice Brennan, joined by Justices Marshall and Blackmun, argued that the majority's decision to uphold an Illinois statute restricting public funding of abortions was a departure from precedent set in previous cases such as Roe v. Wade and Doe v. Bolton which affirmed a woman's constitutional right to choose whether or not to terminate her pregnancy without undue interference from the state. They contended that this law effectively discriminated against indigent women by denying them equal access to medical services solely because of their poverty, thus violating their Fourteenth Amendment rights to equal protection under the law. The justices also expressed concern about potential harm caused by forcing poor women into carrying unwanted pregnancies due to financial constraints or resorting unsafe illegal abortions out of desperation.