The Ex parte SLATER case in 1917 involved a public administrator, Slater, who was petitioning for the right to administer an estate. The Supreme Court ruled that it had no jurisdiction over the matter because it did not involve any federal questions or constitutional issues. Instead, they determined that this was a state issue and should be handled by local courts. The court also noted that even if there were grounds for federal involvement, Slater would still need to exhaust all possible remedies at the state level before appealing to them. This decision reinforced principles of federalism and judicial restraint by emphasizing respect for states' rights and limiting unnecessary intervention from higher courts.

The dissenting opinion in the Ex parte Slater case argued that the court had overstepped its jurisdiction. The justice believed that it was not within the Supreme Court's power to decide on matters of state law, such as probate and inheritance issues, which were central to this case. They contended that these matters should be left to individual states' courts for interpretation and application according to their respective laws. Furthermore, they disagreed with the majority's decision because it could potentially disrupt established legal procedures at a state level by imposing federal interpretations of local laws.