Your chart is a bit stunning. It is pretty much the opposite of how I remember it. If this was the case how come there were all those stories about why the polls had it so wrong? Some thing fishy here.
I think it’s just polls of people from Georgia, a solidly conservative state.
Source of 2016 Georgia head-to-head polls:
https://www.realclearpolitics.com/epolls/2016/president/ga/georgia_trump_vs_clinton-5741.html
I agree. I remember being I shock when Trump won because Hillary was up
everywhere, it was inevitable, etc. etc. Literally on Election Day Trump had a slim to zero chance of winning.