Carson doesn't have any record and he has to give voters a reason as to why they should should elect him president. In evaluating him we have no choice but to look at him as an individual; his character, the way he speaks, the way he presents himself, etc., because there’s nothing else. Some parts of his personal story may be relevant or irrelevant to that assessment. Therefore, whether or not what he says is credible could make or break his chances of becoming president.