What prevents one branch of government from gaining too much power?

Checks and balances is the correct answer because it refers to the system established by the Constitution that ensures no one branch of government—executive, legislative, or judicial—can dominate or exert excessive control over the others. Each branch has specific powers and responsibilities, as well as the ability to monitor and limit the actions of the other branches. This framework is vital for maintaining a balance of power, as it encourages cooperation and consensus among the branches while also providing a mechanism to address any potential overreach.

While judicial review and separation of powers are important concepts in the U.S. governmental system, they support the overall framework of checks and balances. Judicial review allows the courts to assess the constitutionality of legislative and executive actions, acting as a check on those branches. Separation of powers delineates the functions and powers of the different branches, but without checks and balances, there would be no mechanism to prevent any branch from becoming too powerful. Constitutional amendments can modify the government structure or its functions, but they do not inherently prevent the concentration of power within any single branch. Therefore, checks and balances is the most direct answer to how power is kept in equilibrium among the branches of government.