Lobrano v. Nelligan 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 held in a federal prison. The case arose when a prisoner, Lobrano, was held in a federal prison in Louisiana. Lobrano sought a writ of habeas corpus from the state court, which the court granted. The federal government then 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 prerogative, and that the state court did not have the authority to interfere with the federal government's power to imprison individuals. The Court also noted that the writ of habeas corpus was a fundamental right, and that the federal government had the exclusive power to protect this right. The Court's decision in Lobrano v. Nelligan established that the federal government had exclusive authority over the writ of habeas corpus, and that state courts could not interfere with the federal government's power to imprison individuals. This decision has been cited in numerous subsequent cases, and has been used to support the federal government's authority to imprison individuals.

In Lobrano v. Nelligan, the Supreme Court was tasked with determining whether a contract between two parties could be enforced when it had been made without consideration and in violation of public policy. The majority opinion held that the contract should not be enforced because it violated public policy; however, Justice Swayne dissented from this decision on the grounds that contracts are generally enforceable unless they violate some positive law or statute. He argued that since there was no such law prohibiting this particular agreement, then it should have been upheld as valid and binding upon both parties involved. Furthermore, he stated that even if an agreement is made without consideration or violates public policy, courts still have discretion to uphold them depending on their circumstances. In conclusion, Justice Swayne believed that while agreements must adhere to certain standards of morality and legality in order for them to be legally binding upon all parties involved; nevertheless exceptions can sometimes exist where justice demands so long as those exceptions do not conflict with any existing laws or statutes