The U.S. Supreme Court case Dennis C. Vacco, Attorney General of New York, et al. v. Timothy E. Quill et al., 1996 revolved around the issue of physician-assisted suicide and whether it was a constitutionally protected right under the Fourteenth Amendment's Equal Protection Clause as argued by Dr.Quill and his co-respondents who were terminally ill patients wishing to end their lives with medical assistance from physicians like Dr.Quill . The court ruled in favor of Vacco stating that there is a legal distinction between letting a patient die (refusing treatment) and making that patient die (assisting in their suicide). It concluded that New York laws banning assisted suicide did not violate the Constitution because they treated everyone equally - no one was allowed to assist in suicides regardless of their health status or profession.

In the dissenting opinion for Vacco v. Quill, Justice Stevens argued that New York's ban on physician-assisted suicide was unconstitutional because it violated the Equal Protection Clause of the Fourteenth Amendment. He contended that there is no moral or constitutional distinction between a doctor withdrawing life-sustaining treatment at a patient's request (which is legal) and a doctor prescribing medication to hasten death at a patient's request (which was illegal under New York law). Both actions are intended to hasten death and respect patient autonomy, so treating them differently under law seemed arbitrary and discriminatory. Furthermore, he argued that terminally ill patients who are not dependent on life support should have the same rights as those who are. The state’s interest in preserving life does not justify an absolute prohibition against "aid in dying," especially when such aid could alleviate unnecessary suffering.