So, you want to consider aspects of character?  Two of the judges were appointed by Democrat presidents.  The only one appointed by a Republican is Judge Callahan, approved by every Democrat senator.  A profile last year in The Daily Journal explained:
"A hoofer with a sense of humor, Callahan likes to surprise judicial and legal gatherings by starting discussions about serious topics and ending with a quip about appellate judges who tap dance around issues. She then pulls off her black robe to reveal a sequined costume and tap shoes.
She's been known to hop on a tabletop or in one case on a judicial bench during these special events and do some pretty impressive steps. "I may be the highest ranking tap dancer in federal court," Callahan said with a grin during a recent interview in her chambers in the Sacramento federal court building. "It is fun and it has a certain shock value.""
http://www.acslaw.org/acsblog/who-is-consuelo-callahan