I'd have to look up the relevant cases but in the 1940s SCOTUS sometimes overturned itself within a few years or even months. For instance, they ruled that schools could compel students to stand for the Pledge of Allegiance, rejecting a Free Exercise argument from a Jehovah's Witness... and a few years later reversed themselves on Free Expression grounds (which is actually stronger, because it means you don't need any sort of reason to refuse to stand for the Pledge or the anthem or salute the flag or whatever).