Final answer:
The allocation of powers between the states and the federal government is most closely related to the constitutional principle of federalism.
Step-by-step explanation:
One of the most closely related parts of the U.S. government to the constitutional principle of federalism is the allocation of powers between the states and the federal government.
According to the U.S. Constitution, any powers not specifically granted to the federal government belong to the states themselves.
This division of powers ensures that both the federal government and the states have their own areas of authority and can work independently within their respective realms.