What mechanism prevents one branch of government from becoming too powerful?

The mechanism that prevents one branch of government from becoming too powerful is the system of checks and balances. This concept is integral to the structure of the U.S. government, which is divided into three branches: the legislative, the executive, and the judicial. Each branch has specific powers and responsibilities, and the design ensures that these branches can monitor and limit each other's activities.

For example, the legislative branch has the power to make laws, but the executive branch can veto those laws. Furthermore, the judicial branch has the authority to interpret laws and can declare laws or executive actions unconstitutional, effectively nullifying them. This interplay allows for the maintenance of power equilibrium and ensures that no single branch can dominate the government or operate without accountability.

This balance is crucial in safeguarding democratic principles and protecting individual rights. The other choices—majority rule, popular sovereignty, and executive privilege—while important concepts in governance and law, do not serve the specific purpose of preventing the concentration of power within one branch. Majority rule pertains to decision-making processes, popular sovereignty emphasizes the authority of the people, and executive privilege relates to the confidentiality of certain communications; none directly address the balance of power between government branches.