Final answer:
The framers of the Constitution divided sovereignty into state and national powers because of their belief in the separation of powers and the need for checks and balances.
Step-by-step explanation:
The most probable explanation for the division of sovereignty into state and national powers in the Constitution was the framers' belief in the separation of powers. They wanted to prevent any one part of the government from becoming too strong, so they divided the national government into three separate branches and assigned different responsibilities to each one. This division of power also created a system of checks and balances, where each branch could restrict the actions of the others.