Too Long; Didn't Read
The question resembles the question ‘what makes an effective politician?*’ where the answer(s) differ so wildly as to what people want to see in personality, standpoints, and qualifications. We have come to a simple mechanism for answering the question: we vote, we ask people for their opinion, and acknowledge answers are subjective and opinions will differ. By no means is this a perfect way to tackle the issue, e.g., we might lament that pure rhetorics gives an advantage in campaigning but doesn’t translate to great governance.