Thanks SRS. Every way I tried to get into the 538 page took me back to the ABC page, with no explanation for the magical mystery tour.

I tried to find other reliable polling sites but at least one looked skewed in favour of Trump.

This article shows a popularity polling graph and provides some commentary:

Brookings: Trump’s first 5 weeks in the polls

Also I'm halfway through watching a documentary called Adolf Hitler: Decoding a Dictator

It is scarily similar to Trump's rise to power.