The problem comes in that even if you came up with a way to really educate voters and vote judges out, people wouldn't know what to do. Most people aren't educated in even the MOST BASIC aspect of legal proceedings - that is, that the judge is there to apply the law to a set of facts, while following any rules state/fed of criminal or civil procedure - and that's IT.
For example, to hear most / average person talk about recent Supreme Court decisions, including our more liberal friends on AWF, you would think the Supreme Court's job was to effect a certain common sense outcome. That's not the case. Their job is to apply the law (or constitution) to a set of facts. It is entirely possible, and in fact extremely common, that such a correct application occurs even with a regrettable outcome. The public doesn't get that.
They only look at the outcome and say "How could they do that? Don't they support [insert "abortion rights", "the EPA", etc]"