Final answer:
The Senate must approve all presidential appointments, including judges of the Supreme Court, as part of the checks and balances system established by the U.S. Constitution.
Step-by-step explanation:
The Senate must approve all appointments made by the President according to the U.S. Constitution. This includes ambassadors, other public ministers and consuls, and most notably, judges of the Supreme Court. The President's power to nominate these officials is part of the system of checks and balances detailed in the Constitution, ensuring that no single branch of government can operate without the oversight of the others.
The requirement for Senate approval means that appointments are subject to a majority vote, a process that can sometimes lead to contentious confirmation hearings.