“The Constitution does not set any requirements to be a Supreme Court justice. You don’t have to be a judge or even a lawyer.
The Constitution states that a nominee can only be confirmed with the “advice and consent” of the Senate, which is not defined, giving Senators a lot of discretion.
In the last sixty years, nomination votes have become more ideologically charged. In 1987, Supreme Court nominee Robert Bork was rejected, and the term “being Borked” became the nickname for a nominee’s rejection.
In 1991, the Senate held intense hearings for Justice Clarence Thomas, who won confirmation by a vote of 52 to 48 – the narrowest margin in U.S. history.
The filibuster is also available to block a Supreme Court nominee. It has been used only one time, unsuccessfully in 2006, against the confirmation of Justice Samuel Alito.”