In a Parliamentary system, the "prime (first) minister" is chosen by his/her own party, not the population. Therefore a Prime Minister is always an insider, a professional party member, and the possibility of an outsider like Donald Trump coming in to "shake things up" in countries like Australia or England is virtually nil.
The party can even oust a sitting Prime Minister and switch the country's main leader at will, without any consent of the people, as happened from 2010-2015 when Australia had 5 different prime ministers in 5 years! Though Democrats would love to override the will of the people, ousting Donald Trump as President will never happen.
