Individual and socio-political character are the primary determinants of an individual’s, including politician’s, thinking and behavior. For example, is presidential candidate, Donald Trump simply a shrewd, controlling bully in full charge of himself regarding his bid for the presidency or is he just a loose cannon and a blowhard? This distinction depends on whether he is simply a phallic narcissistic character with an oral unsatisfied block, a manic depressive (“bi-polar”) character or a sociopathic character.
In the first case his judgment would be intact and would not detrimentally affect his job as president. In the second and third cases he would be a disaster. We need to know more about his decision making process and his past history in order to determine his capacity for good judgement.