I was in fb groups at the time (I loved them, but had to ditch fb because of their constant suppression of facts) where people would report literally voting for Bernie and seeing the vote change on screen to Hillary. I think when he ran in 2020 and they tried to call the caucus for Buttigieg, he
gave up, because even though they had to admit Bernie won because with the caucus, there's a HUMAN record, he realized they were going to do whatever it took, to make him "lose." Truly think he was optimistic to believe if he just got some more votes this time (and he would've!), he'd make it.