Just for reference, I came to this sub earlier and asked about Trump here. I think this essay does a good of explaining Trump's succes in a paragraph towards the end:

Have we really gotten that much stupider? Probably not. More likely, as with the economic changes wrought by globalization and automation, we are more or less the same, but the playing field has changed, empowering some actors at the expense of others. Or put another way: no internet, no Trump. Just as some people are much better at playing basketball than baseball, the nature of media environment primordially shapes the way in which information is disseminated, processed, and understood. As a technical economic issue, the collapse in the price of entry (manifested most dramatically in the staggering rise of social media) has undermined the practice of reasoned discourse. A now-quaint allegory for the pathologies of the internet culture can be seen in the emergence of cable television, as falling costs of production and a multiplicity of viewing options led to smaller audiences and an even more intense fight for ratings shares, an environment which encouraged attention-getting outrageousness. The internet is exponentially more pernicious: entry is free, accountability is absent, and — here we are more stupid — the ability of people to distinguish between fact and fiction has virtually vanished. We are living in a post-fact, post-rationalist, post-deliberative society, in which people believe what they want to believe, as if they were selecting items from different columns of a take-out menu. This is an environment that plays to the strengths of a media-savvy celebrity demagogue, who, even when not purposefully trafficking in Orwellian lies, has shown an utter disregard for the known truth regarding events large and small, from claims of witnessing non-existent crowds of Muslims cheering the collapse of the twin towers to planting golf-course plaques commemorating imaginary civil war battlefields.