"The appointment of a Supreme Court Justice is an event of major significance in American politics. Each appointment is of consequence because of the enormous judicial power the Supreme Court exercises as the highest appellate court in the federal judiciary. Appointments are usually infrequent, as a vacancy on the nine-member Court may occur only once or twice, or never at all, during a particular President’s years in office. Under the Constitution, Justices on the Supreme Court receive what can amount to lifetime appointments which, by constitutional design, helps ensure the Court’s independence from the President and Congress.
The procedure for appointing a Justice is provided for by the Constitution in only a few words.
The “Appointments Clause” (Article II, Section 2, clause 2) states that the President “shall
nominate, and by and with the Advice and Consent of the Senate, shall appoint ... Judges of the
supreme Court.” The process of appointing Justices has undergone changes over two centuries,
but its most basic feature—the sharing of power between the President and Senate—has remained
unchanged: To receive appointment to the Court, a candidate must first be nominated by the
President and then confirmed by the Senate..."
U.S. Supreme Court