The idea of court balance comes from liberal minds, you are right. I remember when Bush filled the two vacancies on the Supreme Court, and Chuck Shumer said that they had to consider Judge Alito very very carefully. The reason, Shumer said, is because he was being appointed to “the O’Connor seat” on the court, He said that the O’Connor seat was a swing seat, or some such talk.
Of course we all know there is no “O’Connor” seat, or certain seats on the court reserved for moderate, liberal, conservative, black, women, or anyone else. This is an example of liberals saying something and not being challenged, and then it becomes accepted truth. Millions of people now think that the court should reflect a certain balance. Shumer and his colleagues on the Senate Judiciary Committee were less antagonistic towards Judge Roberts than towards Alito. To them, replacing the late Justice Rehnquist with another conservative didn’t upset the balance of the court, but replacing the moderate/liberal O’Connor with a strong conservative caused them fits.
“Where do the libtards get this theory that the SCOTUS must remain “In Balance”
They weren’t worried about it during the 1960’s.