In the case of Arsenault v. Massachusetts (1968), the United States Supreme Court ruled that a defendant in a state criminal trial has the right to counsel during an appeal, even if they cannot afford one. The petitioner, Richard Arsenault, was convicted for armed robbery in Massachusetts and sought legal representation for his appeal but was denied because he could not afford it. He argued this denial violated his Sixth Amendment rights under the U.S Constitution which guarantees every citizen's right to legal representation in all critical stages of prosecution. The Supreme Court agreed with him and reversed his conviction on grounds that failure by states to provide indigent defendants with appellate counsel is unconstitutional as per Gideon v Wainwright (1963) ruling which extended this constitutional guarantee from federal trials to state trials.

In the dissenting opinion for Arsenault v. Massachusetts, Justice Harlan argued that the majority's decision to retroactively apply new rules of criminal procedure was a departure from established legal principles and could lead to an overwhelming number of appeals. He contended that such changes should only be applied prospectively, not retrospectively. Furthermore, he expressed concern about the potential impact on state courts and their ability to manage caseloads if they were required to reconsider convictions based on new federal standards. In his view, this would undermine states' rights and disrupt the balance between state and federal authority in matters of criminal justice administration.