Populism isn't an ideology, it's a rhetoric. It's the rabble rousing of people who blame the established order, whatever it may be, for all their problems. Populist leaders are always the ones who tell these disaffected people who don't really understand how anything works, that they are really correct, and everyone else is a sheep who promote the lies told by the establishment. Populism is almost entirely the intellectually bankrupt rantings of people who are looking for someone to blame.