Short Answer 
The U.S. government employs a checks and balances system, dividing power among the Executive, Legislative, and Judicial branches to prevent any one entity from dominating. Congress can curb presidential power through legislation, veto overrides, and control of funding, while the Judicial Branch ensures compliance with constitutional standards and holds the President accountable to the electorate.
Step 1: Understanding Checks and Balances
The United States operates under a system known as checks and balances, which ensures that no single branch of government can overpower the others. This system divides power among three branches: the Executive (the President), the Legislative (Congress), and the Judicial (the Courts). Each branch possesses specific authority to regulate and influence the actions of the other branches, protecting the nation from authoritarian rule.
Step 2: Legislative Power of Congress
Congress wields significant authority to limit presidential power through various mechanisms. Key powers include:
- The ability to pass legislation that can directly influence presidential actions.
- The power to override a presidential veto with a two-thirds majority vote in both houses.
- Control over federal funding, enabling Congress to finance or defund executive initiatives.
Step 3: Judicial Review and Public Accountability
The Judicial Branch plays an essential role by conducting judicial review of presidential actions, ensuring they comply with the Constitution. If a President oversteps their boundaries, the Supreme Court can declare their actions unconstitutional. Moreover, the President is held accountable to the public through elections. A President who acts against the interests of the populace risks losing public support and can ultimately be voted out of office, reinforcing democratic accountability.