What is it called when state and local government share their powers or duties, with each other ?

Federalism

Explanation:

Federalism describes the system of shared governance between national and state governments. The states and the federal government have both exclusive and concurrent powers, which help to explain the negotiation over the balance of power between them

Federalism describes the system of shared governance between national and state governments. The states and the federal government have both exclusive and concurrent powers, which help to explain the negotiation over the balance of power between them.

Explanation:

julius caesar turned the roman republic into the roman empire by coming in and taking the "dictator" role during the time of a civil war (elites vs lower classes) winning battles and reputation, then declaring him dictator for life

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