His narrative is a bit wonky but the general idea is true. https://en.wikipedia.org/wiki/2016_Democratic_National_Committee_email_leak
Trump’s presidency was so chaotic that it made us forget that the DNC Chair resigned mid campaign because of this scandal.
I said basically the same the article says a couple of days ago and was pelted with a gazillion negative votes. Centrists are averse to learning from mistakes, otherwise they wouldn’t be centrists.