Federalism established the way the US government operated by articulating state governments under the general government.
Established the separation of the federal government in 3 powers: The Executive (President), The Legislative (Congress), and Judicial (The Supreme Court).
Established checks and balances, which helps maintain the stability of power among the 3 branches of government. The President can veto a Law that Congress has passed, however, Congress can override that veto if it gets enough votes. On the other hand, the Supreme Court can declare a law passed by Congress as unconstitutional. Finally, The Supreme Court interprets the laws and makes decisions over them but it is the President who ultimately nominates Supreme Court Judges.
