Doesn’t the system already work like this? The federal government is responsible for the things enumerated in the Constitution (accepting, as you say, that the

Doesn’t the system already work like this? The federal government is responsible for the things enumerated in the Constitution (accepting, as you say, that the scope of these powers has become wider in practice over time). The states are responsible for everything else. The “boring yet important” decisions are made by unelected bureaucrats rather than politicians.