In the case of Coleman et al. v. Alabama in 1969, the U.S Supreme Court ruled that defendants are entitled to legal counsel during preliminary hearings under the Sixth Amendment's right-to-counsel provision. The appellants, six black Alabamians charged with murder, were not provided with counsel at their preliminary hearing where critical decisions regarding bail and pleas were made without any legal advice or representation for them. They argued this violated their constitutional rights under both the Sixth and Fourteenth Amendments. The court agreed in a 5-4 decision stating that a preliminary hearing was indeed a "critical stage" in criminal proceedings where potential substantial prejudice could occur if an accused is not represented by counsel.

In the dissenting opinion for Coleman et al. v. Alabama, Justice Harlan disagreed with the majority's decision to extend the right to counsel during preliminary hearings under the Sixth Amendment of U.S. Constitution. He argued that this expansion was unnecessary and could potentially burden state criminal justice systems without significantly improving defendants' rights or trial outcomes. Justice Harlan believed that a defendant’s constitutional rights were adequately protected by existing procedures such as grand jury indictments and trials where legal representation is already required. Furthermore, he expressed concerns about federal courts intervening excessively in state court proceedings which might undermine states’ abilities to manage their own judicial processes effectively.