In McConnell v. Rhay, Penitentiary Superintendent (1968), the U.S. Supreme Court ruled that a state court's failure to appoint counsel for an indigent prisoner during a post-conviction hearing violated his constitutional rights under the Fourteenth Amendment’s Due Process Clause. The petitioner, McConnell, was serving time in prison and had filed several habeas corpus petitions challenging his conviction on various grounds including ineffective assistance of counsel and coerced confession. However, he was not provided with legal representation during these proceedings despite being unable to afford one himself due to financial constraints. The Supreme Court held that when such hearings involve substantial issues or disputed matters of fact which could potentially result in release from custody if resolved favorably for the defendant; it is essential that they have access to legal aid so as not be disadvantaged by their lack of knowledge or expertise in law.

In the dissenting opinion for McConnell v. Rhay, Justice William O. Douglas argued that the petitioner's constitutional rights were violated due to a lack of counsel during his post-conviction proceedings. He believed that this denial was contrary to the principles established in Gideon v. Wainwright and other cases which affirmed an individual’s right to legal representation in criminal trials and appeals processes. In addition, he expressed concern about potential coercion or manipulation by prison officials when inmates are left unrepresented legally while incarcerated, especially given their vulnerable position within such institutions.