Supreme Court
Just think of all the trouble that could have been avoided if Americans always had understood the interstate commerce clause of the Constitution the way the current Supreme Court majority does: as a magic box into which the government plunges its arm and pulls out, lo!, exactly the power it was looking for. Like some four-dimensional cauldron in a Harry Potter book, it's an inexhaustible stock of authority crammed into one little space. Think of it! Want to do away with slavery? No need for a blood-boltered civil war. Just wave your wand and invoke the commerce clause. Yet somehow, the very founders who wrote the Constitution overlooked this aspect of their work.