Why was/is it so close?
1) Tribal voters -the hard core of people whose families have always voted for one party and will always vote for that party, regardless of policies and personalities. It's as ingrained in them as their religion and equally devoid of thought.
2) Anti-intellectualism. Between 40 and 50% of any given population are dimwits who watch sports, soap operas and reality TV and who own no books. These people see Trump (and Boris Johnson) as one of their own. Someone who will save them from the clever-clogs, know-it-all types who've been running the country into the ground since the War. 'Practical' people (sic).
3) The disenchanted non-voter. "It doesn't matter who you vote for - the government always gets in!" Say those who've been there, done that and seen nothing change for too many years. Joined by young people who see politics as something done by old people. Put somebody under 50 - or preferably under 40 -up there and they'll vote for them!
I could go on, but there's no point, Umair. You know a lot of stuff about a lot of stuff. but you don't seem to know much about people! (Anyone who can describe the Germans as 'wise and gentle' clearly doesn't know much about European history, either!) Fact is, that the majority of people don't know what we know, or think as we think. Most of them would barely understand much of the vocabulary folk like you and I use habitually! They don't want to, they just want to get on with their own lives because that's what they understand.
Until and unless we can educate everyone to a level where understanding of such issues is possible for 'ordinary' people, democracy will continue to throw up its Trumps, Thatchers and the occasional Hitler.