Not a single person who knew him before says this is a surprise.

Here's a good example if how this happened.

https://www.reddit.com/r/SocialDemocracy/s/b8IISKdAPO

Here is a discussion with people who are almost certainly genuinely leftists. They were given clear information from people who know the guy that he's full of shit. No one wants to accept that narrative because it leaves them in the position that all American leftists fund themselves in eventually: no one on their ballot actually supports their interests.