Judges today have more power than at any time in history. Judges' rulings now alter, overturn, or through interpretations effectively create new laws to such an extent that it could be argued that the courts are quickly becoming another legislative branch. As such, it is important that these judges have some accountability to the people. Plenty of states already have elected judges and it has worked fine. There is no reason this could not be expanded.
In a judges election, not many people may vote. That gives power to those judges who can afford to mobilize voters whose best interests they promise to protect. This leaves the chance for judges to be elected that may not serve justice fairly for everyone. Judges should be put into place based on merit and past accomplishments.