Donald Trump already has everything a man of 69 could wish for...money, fame, family, health etc. What do you think is missing from his life? If he gets elected, and can really change the direction of country, that would be a crowning legacy to his life, and my guess is that is what he is after.Why would he give that up, to have everything he has ever said or done to be scrutinized with a fine-tooth comb.
I think it is out of fear of where this country is headed. Question his solutions, but I don't question his motives.