Trump is nothing but a collection of dirty laundry.  Blatant lying, insulting the handicapped, stiffing workers, being rude to contestants on his game show, treating women with disdain (and possibly worse).  I can conceive of few blackmailable matters to which he has not already either admitted or proudly claimed.  But they had no negative effect on his supporters.  He could boil and eat babies and his supporters would hardly blink.  So how can anyone fear he may be susceptible to blackmail?