I understand just fine. When the used car salesman tells me he will maintain my car for 6 months and give me a 2 yr. parts and labor warranty on the drive train you bet your ass that I'll make sure all that is in the contract I sign before I hand over any money. It's the contract that counts.
Apparently it's you who are failing to understand. The States don't call the shots, either, all they did is ratify a written contract. It's the written contract that's the controlling factor here, not the States nor the people that wrote the contract.
here, since you want this:
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.
its is the state themselves which created the compact, under the constitution which setup the federal government, it delegated to the federal government 18 enumerated duties only,
all other powers belong to the states, per the 10th amendment.
“The powers delegated by the proposed Constitution to the federal government are
few and defined . . . to be exercised principally on external objects, as war, peace, negotiation, and foreign commerce.” – James Madison, Federalist 45
“This specification of particulars [the 18 enumerated powers of Article I, Section 8] evidently excludes all pretension to a general legislative authority, because an affirmative grant of special powers would be absurd as well as useless if a general authority was intended.” – Alexander Hamilton, Federalist 83
and as far as commerce goes, here is what Madison says about it in the first line of federalist 42, where he states becuase under the articles of confederation there is a defect of power, becuase of the regulation of commerce
between the members,(meaning the states), not inside the states.
Article 1, Section 8, Clause 3 (Commerce)
Document 9
James Madison, Federalist, no. 42, 283--85
22 Jan. 1788
The defect of power in the existing confederacy, to regulate the commerce between its several members, is in the number of those which have been clearly pointed out by experience.
http://press-pubs.uchicago.edu/founders/documents/a1_8_3_commerces9.html