How has the concept of federalism shaped the balance of power between the nation

How has the concept of federalism shaped the balance of power between the national government and state governments in the United States? What are the advantages and disadvantages of this system of governance, and how has it influenced policy-making and political dynamics in the country? Provide specific examples to support your arguments. Must be a minimum of 300 words.
Key points
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.
The federal government can encourage the adoption of policies at the state-level through federal aid programs.