Final answer:
The system of checks and balances limits presidential power through the ability of Congress to override vetoes with a two-thirds vote, the requirement of Senate confirmation for presidential appointments, and congressional control over military funding and declarations of war.
Step-by-step explanation:
The system of checks and balances limits the power of the president by ensuring no single branch of the United States government can operate without oversight and approval from the other branches. A specific example is that all presidential vetoes can be overridden by Congress with a two-thirds vote in both the House and Senate, turning a bill into law despite the president's rejection. This serves as a check on the president's power to unilaterally block legislation. Additionally, the Constitution gives Congress the sole power to introduce legislation, the Senate must confirm presidential nominees and treaties, and the House can impeach the president. Hence, the president must work within these constraints, resulting in a balance of power that requires cooperation and consent between the executive and legislative branches. The Senate also plays a crucial role in the appointment of federal judges, including Supreme Court justices, as the president's nominees require Senate confirmation, further keeping the president's appointment power in check.
Congress can also limit presidential powers by controlling military funding and declarations of war, further emphasizing that the president does not have sole authority over military actions. Together, these mechanisms of oversight and the requirement for inter-branch cooperation exemplify how the check and balance system curtails the potential for overreach by the president.