What do you mean? The Constitution is god, pre-existing, and that it delegated powers to the states? ROFTLM*O!!!!! The preamble states that the people of the several states 'do ordain and establish this Constitution'. The people of the respective states, in convention, ratified and delegated (not transferred permanently) powers to the new federal government.
A power-of-attorney delegates authority from an individual or corporation to an agent. The power-of-attorney cannot rescind or transfer power, it's simply a document. The rescinding/transferring is effected by the person/corporation delegating power to begin with.
For the sake of argument, where does it state that the Constitution undelegates powers? Per Amendment X, the powers 'not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.'