I would tend to agree w/ Alexainie that Trump is a “psychopath/business,” while Duterte is more of a sociopath. Those are totally unqualified anecdotal assessments, however. I worked closely w/ one such psychopath for several years in San Francisco…a man who told me that he’d spent a lot of money on shrinks, but inevitably chose to revert each time because anytime his mental state improved, it hurt his business.
As for Duterte’s popularity, I attribute it mainly to unbridled anger’s desire for destruction. I expect to see such destruction soon manifest more strongly in the US. In both cases, we liberal believers in human development have also fallen short. People are impatient. The sad part is that good, solid development policies & programs get wiped out, while voters — in expressing their anger — end up in worse straits than ever. We have failed to communicate and failed to demonstrate in ways the wider population can understand. That’s not unusual among technocrats and needs to change.