The answer to that is actually not complex .... Trump told the lies that the uneducated voters wanted to believe.
When Trump lied saying "I will make America great again!!"
the inbreeds did not ask the very obvious question ... How?
Or indeed even notice that no one has told them previously that America is not great
... Though it is quite obviously an open cess pit of misery, hate and racism. No, exactly like Fox Mulder .... they want to believe.
The exact same thing has happened in the UK for the exact same reason ... There the idiots who would vote for Trump, instead voted for Brexit and Boris Johnson ... Because in the UK they were lied to and told that the EU was the creation of all their problems
and leaving would make the UK 'great again'.
What has crushed both the UK and USA is Post Industrialised service focussed economies ... The UK lost the 60 country GB empire by 1963 and the USA lost the world fiscal hegemony afforded it by the two world wars; gone in effect by 1980 ... 1970 was when Post Industrialisation started in the US & UK.
Neither the US nor UK will be 'great' for centuries, indeed, if ever. But the mug punters
, they don't want to hear that ...... The moronic 50% of any public will always, ALWAYS, readily accept a simple lie over a complex truth.