If you have to amend the Constitution to allow it, it might make more sense to create the Court of Union as the new supreme court. Cases appealed from the federal appellate courts would be heard by the Court of Union where the states have the final word on constitutionality.
That is a really interesting idea! I had never heard of that. We would still need limits on that though, so it doesn’t creep back to where it is now with the Court of Union (or Supreme Court) basically making laws and encroaching on the state’s rights and responsibilities, and always marching downhill toward centralization.