Final answer:
Congress is the ultimate controller of the federal budget, although the President plays a significant role in proposing it. The Senate confirms presidential appointments to the federal bureaucracy, which is part of the system of checks and balances.
Step-by-step explanation:
The controller of the federal budget is Congress. The President, as the head of the Executive Branch, initiates the budget process by submitting a proposed budget to Congress, outlining proposed revenues and expenditures. However, it is ultimately Congress that holds the power to approve, amend, or reject the budget. The President's role involves setting the fiscal policy direction and working with the Office of Management and Budget, along with economic advisers, to craft the budget. Congress, after receiving the budget, conducts a series of reviews and votes that lead to the finalization of the federal budget.
Apart from the budget, the President has a degree of control over the federal bureaucracy by appointing heads of cabinet departments and executive agencies, subject to Senate confirmation. As a check and balance, the legislative branch can influence the court system through actions such as Senate approval of judicial appointments and congressional power to rewrite laws or withhold funding to implement court decisions.