Final answer:
Madison referred to how the Constitution protects people's rights through federalism and the separation of powers.
Explanation:
Madison was referring to the fact that the Constitution protects the rights of the people through federalism and the separation of powers when he wrote that 'a double security arises to the rights of the people'. This means that by having power divided between the national government and the states, as well as among different branches of government, the rights of the people are safeguarded through a system of checks and balances.
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