Dear Mr. Madison,
Question: What is the 10th Amendment for?
Answer: First, thank you for waking me from my rest. Second, who is this TheBigIf? Kinda reminds me of our old maid.
“[The Constitution] was constantly justified and recommended on the ground that the powers not given to the government were withheld from it; and that, if any doubt could have existed on this subject, under the original text of the Constitution, it is removed, as far as words could remove it, by the [10th] amendment, now a part of the Constitution, which expressly declares, ‘that 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.’
Furthermore
The states, then, being the parties to the constitutional compact, and in their sovereign capacity, it follows of necessity that there can be no tribunal, above their authority, to decide, in the last resort, whether the compact made by them be violated; and consequently, that, as the parties to it, they must themselves decide, in the last resort, such questions as may be of sufficient magnitude to require their interposition