The answer to this question depends on the state of practice. 28 U.S. states require you to be a practicing lawyer to preside over cases. Fourteen states accept non-lawyers as judges, but a defendant who receives a jail sentence from such a judge has the right to a new trial under lawyer-judge. Eight states grant non-lawyers unlimited judgeship.
This scenario would require a President to select a non-attorney and senate's approval for a non-lawyer to turn judge. In some states, the only requirement is to get votes in the jurisdiction to become a justice of the peace without being a lawyer first.  Therefore, before figuring out how to become a judge, get to know your state’s laws and regulations.