Why do people feel the Supreme Court needs to have a demographic representation?

I can understand the need for Congressional representation, but our high court is intended to interpret the laws created by the people and their elected officials. If they are using a sound judicial philosophy, what's the need for demographic representation on the court. If Judge Sonia Sotomayor is the best qualified based on her credentials and judicial philosophy, then so be it! I just don't think that is the basis for her nomination. Sotomayor said, "I would hope that a wise Latina woman with the richness of her experiences would, more often than not, reach a better conclusion." Do you really think race has anything to do with judicial interpretation?