"Bernie Bros"

The worst part is "Bernie Bros." Was a repeat of a tactic Hillary already tried

Back in 2008 it was the "Obama Boys"

I didn't remember that it was about hating women. My experience of it was a certain group of Berie supporters who were super enthusiastic but also pretty toxic about their support for Bernie. I ran into it myself - it was impossible to talk to some of them without getting insulted for honest questions or concerns. And that was with them knowing that I'm pretty far left in my viewpoints. So it often just left a very bad taste in my mouth, which didn't dissuade me from still supporting Bernie (still love him) but I could see how that would polarize a voting base in a moment when you want to unite it.

I didn’t remember that it was about hating women.
It wasn't, there was just a sizeable segment of 4-chan types who liked Bernie and the left, being unable to rally together for anything, broadly attacked these dudes for existing and not adoring Hilary Clinton who was, in case you all missed it, a woman.
I'm sure there were some performative loud voices from assholes trying to poison the well, but our side hasn't learned to ignore this shit, and never will. Leftists are as easily manipulated as MAGA but in different ways, ya'll just haven't figured it out yet.
- Leftists are as easily manipulated as MAGA but in different ways, y'all just haven't figured it out yet.
  Nobody is immune to propaganda. Something we must all remind ourselves.

They never supported Bernie's policies. It wasn't very many, but there were a bunch of Bernie Bros in 2016 who switched from him to Libertarian candidate Gary Johnson. There is very little policy overlap between the two aside from being contrarian. That's all they were doing: being contrarian without any actual policy ideas.

However, the vast majority of Bernie primary voters did vote for Hillary in the general that year.

there were a bunch of Bernie Bros in 2016 who switched from him to Libertarian candidate Gary Johnson. There is very little policy overlap between the two aside from being contrarian
Only if you insist on viewing politics through a left-right axis and ignore the authoritarian-libertarian axis. Or if you're weirdly using "contrarian" as a synonym for "not authoritarian," which (considering the status-quo candidates) I guess makes sense.
- The political compass is an only slightly better model than the one that's based on 18th century French parliament seating arrangements.