The Constitution empowers the president to appoint Supreme Court justices, subject to the “advice and consent” of the Senate. In theory, confirmation hearings allow senators to ask probing, incisive questions of the nominee, cannily gauging their fitness for a coveted life-tenured position on the bench. In practice, hearings typically consist of senators droning on about a constellation of topics that may or may not have anything to do with the nominee, the job, or even the law itself. It is like a public job interview, if half the people asking questions were making a big show of barely acknowledging your existence.
For most of the Court’s existence, the Senate voted on nominees without hearings or fanfare of any sort. It confirmed Edward Douglass White, for example—a former Confederate who for some reason was still allowed to spend 27 years on the Supreme Court after the Civil War ended—as an associate justice and later as the chief justice. Both times, lawmakers confirmed him on the same day of his nomination, and both times by voice vote.
As is the case with many institutions in America, the powers that be grew very concerned about the integrity of the process once non-WASP men started getting involved. In 1916, when President Woodrow Wilson nominated Louis Brandeis, a prominent labor lawyer and the first Jewish nominee, the Senate Judiciary Committee suddenly decided that it better hear from some witnesses on the subject. After his opponents exhausted their supply of thinly-veiled anti-Semitic tropes, Brandeis—who, wisely, did not bother to show up to first-ever Supreme Court confirmation hearing—was confirmed by a 47-22 vote. Two decades later, Felix Frankfurter—another Jewish nominee—agreed to attend, but didn’t say much on the grounds that his record spoke for itself. The Senate confirmed him unanimously.
Not until the nomination of John Marshall Harlan II in 1955 did confirmation hearings start to resemble the confirmation hearings of today. As Professor Carolyn Shapiro has noted, this was not a coincidence: One year after the justices in Brown v. Board of Education declared school segregation unconstitutional, the Senate’s angriest racists needed a Court-adjacent forum for airing their grievances, and Harlan’s hearing presented them with a convenient one. Strom Thurmond, the avowed South Carolina segregationist, announced that he’d take a more skeptical approach to nominees in light of Brown, promising to vote against anyone who was, in Thurmond’s estimation, “disqualified for the trust he would assume.” (It feels like this should go without saying, but Thurmond was physically incapable of imagining a lady Supreme Court justice.)