Answer:
He called them laboratories of democracy because states would experiment with solutions to social problems first and then federal government could take up those programs if they worked and expand them nationwide.
Explanation:
individual liberty is at the heart of this. He protected federalism; the federal principle or system of government in which the power is divided between the national government and other governmental units.
This contrasts with a unitary government, in which a central authority holds the power, and a confederation, in which states, for example, are clearly dominant.