Anything besides a vague promise to be fair means the judge is deciding something before a case goes to trial. Judges shouldn't be advocates. If we want to attract and keep highly qualified individuals who will be impartial and who won't succumb to the will of influential individuals if that is contrary to the law, then Merit Selection is the system to embrace. The concept of term limits for politicians is a popular one. But it's a concept that doesn't work with judges.
Judges learn to be good judges by judging.
Judges need time to develop expertise. We already have the opportunity for limiting a judge's term. After a judge is appointed, he or she is on the ballot within two years. We have independent Judicial Performance Commissions in place to educate voters so that terms could be limited intelligently. There's another control in the Judicial Disciplinary Commission - it can discipline judges, remove them from the bench or encourage them to retire regardless of how long they have served or have until their next retention election.