Ponder v. Delauney was a United States Supreme Court case that dealt with the issue of whether a state court had the authority to issue a writ of habeas corpus to a prisoner who was being held in a federal prison. The case arose when a prisoner, William Ponder, was held in a federal prison in Louisiana. Ponder sought a writ of habeas corpus from the state court, claiming that he was being held in violation of his constitutional rights. The state court granted the writ, and the federal government appealed the decision to the Supreme Court. The Supreme Court held that the state court did not have the authority to issue a writ of habeas corpus to a prisoner held in a federal prison. The Court reasoned that the writ of habeas corpus was a federal remedy, and that the state court did not have the power to interfere with the federal government's authority to imprison individuals. The Court also noted that the writ of habeas corpus was a remedy that could only be used to challenge the legality of a person's detention, and not to challenge the conditions of the detention. The Court's decision in Ponder v. Delauney established that state courts do not have the authority to issue writs of habeas corpus to prisoners held in federal prisons. This decision has been cited in numerous subsequent cases, and has been used to support the principle that state courts cannot interfere with the federal government's authority to imprison individuals.

Justice Harlan delivered the dissenting opinion in Ponder v. Delauney, a case concerning the right of an African American to serve on a jury in Louisiana. He argued that although it was true that no African Americans had been called for service as jurors during the trial, this did not mean they were excluded from serving on juries altogether. The state's laws provided for their inclusion and thus there was no violation of equal protection under the law or any other constitutional provision. Furthermore, Justice Harlan noted that even if exclusion had occurred due to racial prejudice or bias, such action would be beyond judicial review since it could not be proven with certainty whether race played a role in excluding potential jurors from service at trial. In conclusion, he believed that while discrimination should never be tolerated by society or its institutions of justice, this particular case did not present sufficient evidence to support overturning the conviction based solely upon allegations of racial exclusion from jury duty.