I think it's pretty obvious that Trump is getting very high-quality, very sensitive information from many interesting places.
He's made very provocative assertions and predictions that (a) first caused the PC hive to go berserk and then (b) were shown to be true within a few days or weeks.
It wouldn't surprise me at all if it turns out he has someone inside Hillary's organization.
Whether Trump has moles in her organization or not, we should insinuate that he does. Nothing is more corrosive to morale or effectiveness of an organization than a good mole hunt. And for someone as inherently paranoid as Hillary, it would be devastating.