Writing for the Court, Justice William Douglas held that the Sixth Amendment's guarantee of the right to counsel was fundamental to a fair trial and applied to all criminal prosecutions, whether classified as felonies or misdemeanors. Douglas underscored the importance of the right to counsel in ensuring the fair administration of justice, stating that it, “is often a requisite to the very existence of a fair trial.”

Douglas rejected the premise that the right to counsel was limited to serious crimes. He pointed out that the right to a fair trial is compromised if an accused, regardless of the severity of the charge, is tried without the assistance of counsel. He instead argued that imprisonment, even for a brief period, is a serious deprivation of liberty and thus necessitates the appointment of counsel. Douglas emphasized that the Sixth Amendment’s right to counsel was essential for ensuring justice and fairness in all criminal prosecutions, reaffirming the Court’s rulings in Powell v. Alabama (1932) and Gideon v. Wainwright (1963). He explained that “Powell and Gideon suggest that there are certain fundamental rights applicable to all such criminal prosecutions,” and that the Court was “by no means convinced that legal and constitutional questions involved in a case that actually leads to imprisonment even for a brief period are any less complex than when a person can be sent off for six months or more.”

Douglas ultimately held that “absent a knowing and intelligent waiver, no person may be imprisoned for any offense, whether classified as petty, misdemeanor, or felony, unless he was represented by counsel at his trial.” He concluded, “[u]nder the rule we announce today, every judge will know when the trial of a misdemeanor starts that no imprisonment may be imposed, even though local law permits it, unless the accused is represented by counsel. He will have a measure of the seriousness and gravity of the offense and therefore know when to name a lawyer to represent the accused before the trial starts.”