O'Connor said judges should not be elected by politicians because that can send the wrong message about the role of a judge.
"I think there are many who think of judges as politicians in robes. In many states, that's what they are," she said Thursday in an address on history, ethics and law.
Judges should not make decisions based on popular will and must reflect on legal issues in a fair and unbiased way, O'Connor said.
Judges should take more care to recuse themselves if there is a potential for bias, she said.
"They need to avoid sitting on cases if even a whiff of bias can be detected."