What is the assumption behind dual federalism?

Dual federalism is based on the assumption that a clear division between federal and state authority can, and does, exist.

Explanation:- This theory explains that authority between the two levels of United States government, national and state, could be treated equally, live together equally, and hold roughly equal authority. Furthermore, dual federalism believes that federal government controls such functions as national defense, foreign policy, tariff policy, regulation of interstate commerce, postal service, and many others while the State operate in different policy spheres, largely controlling education, welfare, health, and criminal justice.

i think it's the cabinet

where is the passage