For the average citizen this question may never be asked, for those who have gone into a Courtroom it is like a neon light flashing in their face “Who the hell pick this person?”
I will examine King County BAR Association here but most if not all local BAR Associations have similar committees so check your local BAR for specifics in your area.
Members of the KCBA select a committee for Judicial screening, information can be found here KCBA Judicial Screening process, applicants fill out evaluation forms and the process starts.
2012 Governor’s Judicial Evaluation Questionnaire
2012 KCBA Judicial Evaluation Supplemental Questionnaire
Every year the KCBA conducts a survey of their members concerning the performance of the King County Superior Court Judges, they then compile this data into a annual report, here is a example.
2012 KCSC Judicial Evaluation Survey Results