And as you just said. Donald was fact checked. If a politician lies or breaks his promises we have opposition politicians and the media to point it out. And they do point it out, both of those are always big stories.
The real issue is that most people don't bother to engage with it as they have got better things to do with their lives. They don't care that Donald lies. So if they do bother to participate in a vote or an election then they will probably be doing so from a sub-optimal position in terms of being 'informed'
But then 'Poorly Informed' has changed in meaning to become 'Doesn't agree with me' so it is hard to distinguish these days. For example I could say that anyone who voted against Brexit was 'poorly informed'. But the reality is that it's just an insult dressed up.
The best thing we could do for democracy would be to abandon the idea that people who disagree with us do so because they are 'Poorly informed' and start accepting the idea that a more intelligent dialogue is required.