I ignored American politics until 2004 when — inexplicably — George W. Bush was elected for a second term after being unbelievably bad in his first term.
What the Hell was going on?
Jim VandeHei explains why the USA has such extreme politics in 2017: Newt Gingrich, Fox News (1996), MSNBC, CNN, Facebook and later Twitter, Sarah Palin and finally Trump.
Jon Stewart and Stephen Colbert documented the idiocy.
How American politics went batshit crazy
It’s easy to say Americans deserve the politicians they have.
My fear is that other nations will evolve in the direction of the American way. 😦
Rick McCharles 
A lot of what happened on George W. Bush’s watch was not entirely of his making.