Most states make their judicial system submit to the electoral process, from circuit court judges all the way up to state supreme court judges.
We need a consitutional amendment to do the same at the federal level. After a few years on the bench, even the most level-headed individuals are likely to think they're God.
Who would get to vote for them? The people in the judicial district in which they serve? I bet the makeup of the Federal Court in Manhattan, with its large percentage of former big firm lawyers, would change.