Like many questions in social studies, It's really up to you.
Do you think formal qualifications should trump ones ideas? Or should it be opposite, where justices should be picked solely on what they would do as supreme justices.
The question can also apply to say, the President, Should you have a distuinguishable political career, or should anyone be able to run?
Fun related fact: Jimmy Carter, the 39th President of the United States, was a peanut farmer.