The Republicans have always exploited a very unfortunate (IMO) anti-intellectual streak in American culture. EVERY Democratic presidential candidate is bashed for being too intelligent, too knowledgeable, and therefore somehow not to be trusted. GW Bush got elected by saying 'Hey I don't have to know that, I can HIRE someone who knows that!' and 'Vote for me, 'cos I'm just as ignorant as YOU are!'
Trump is much the same. He said he had plans for defeating ISIS quickly, for cutting spending, for replacing Obamacare. THEN he said he'd hire the 'best people' and they would come up with good plans. But like Bush, he's not unintelligent so much as just intellectually lazy. He doesn't want to KNOW things, he wants things to be the way he sees them.
A few months ago he learned that Abraham Lincoln was Republican. This tickled him. He even said 'Hey I bet you didn't know Lincoln was a Republican!' But yeah, we all knew that. When HE learned it, he thought it would be as big a surprise to everyone else as it was to him.
Yeah, his 'base' is proud of their ignorance. Their whole philosophy rests on misinformation so they just HATE to hear that their cherished beliefs are lies. They want a president who reinforces their unfortunate prejudices rather than put them straight.