Final answer:
James Madison believed that federalism is needed in government because it prevents the national government from becoming too powerful and helps to prevent tyranny.
Step-by-step explanation:
James Madison believed that federalism is needed in government because it prevents the national government from becoming too powerful and helps to prevent tyranny.
In Federalist No. 51, Madison explains that the division of power between the national and state governments, as well as the separation of powers within the federal government, ensures that no one part of the government becomes too strong.
Additionally, Madison argues that ambition among elected officials encourages them to limit the powers of other branches, creating a system of checks and balances.