For one, the Constitution already has a legal framework for decentralization, and that is the states. Also, states already have governments etc, so from a prag

For one, the Constitution already has a legal framework for decentralization, and that is the states. Also, states already have governments etc, so from a pragmatic standpoint transferring power to them can potentially be done without setting up new centers of power that overlap existing structures. Unfortunately the Constitution prohibits breaking up states without their consent, so short of a Constitutional amendment it seems unlikely that these advantages could be obtained with entities smaller than the existing states. I agree with your premise (I think); personally I prefer the ninth amendment to the tenth. Certainly however, I would favor d?evolving power to the states instead of pushing power up the totem pole through regionalism.