In Baldasar v. Illinois (1979), the U.S. Supreme Court ruled that a prior uncounseled misdemeanor conviction could not be used to enhance the sentence for a subsequent offense to a felony under an Illinois statute, as it violated the Sixth and Fourteenth Amendments of the Constitution. The case involved Charles E. Baldasar who was initially convicted for theft, which was classified as a misdemeanor since he wasn't represented by counsel and his punishment did not include imprisonment. However, when he committed another theft later on, his previous conviction was used to upgrade this second charge from misdemeanor to felony status under state law - leading him being sentenced to prison term of one-to-three years. He appealed arguing that using his first uncounseled conviction in such manner is unconstitutional because it denied him right to counsel guaranteed by Sixth Amendment and due process rights protected by Fourteenth Amendment.

In the dissenting opinion for Baldasar v. Illinois, it was argued that a prior uncounseled misdemeanor conviction should not be used to enhance the sentence of a subsequent offense to a felony level. The dissenting justices believed this practice violated the Sixth Amendment's guarantee of right to counsel because it allowed an uncounseled conviction, which would normally only result in minor penalties, to dramatically increase punishment for future crimes. They also pointed out inconsistencies in how such convictions were treated across different states and within federal law itself. Furthermore, they expressed concern about potential abuses by prosecutors who might strategically withhold counsel during initial proceedings with an eye towards enhancing sentences later on.