Separation of Power: Powers of a branch of The United States government which would be limited by the powers of another branch to prevent abuses of power and avoid autocracy.
Checks and Balance: Each of the three branches of government can limit one another powers.
Judicial Review: The Judicial Review determines if the Legislative and Executive remains consistent with the constitution.
Federalism: It effect the federal government from doing something to help the people's needs, also causing problems with the states.