As someone who was a huge supporter of Bernie in 2016(Unfortunately i wasn’t able to vote but I did actively campaign for him) I actually didn’t want Bernie to run in 2020. I knew the center left media would do him dirty.
I personally hoped he would back Elizabeth Warren who has strong progressive values, smart laid out policy plans even before she ran but is also has some respect in the center left sphere of things. personally I won’t decide who I want to vote for until after 2 or 3 debates as I believe everyone should at least have some sorta shot(Although I have a couple I know I wont vote for like Biden or the former house member of John Delaney). I think the best way to have progressive/Social Democratic values to hold in America, from my perspective, is through local and state level elections plus primary out any congress people like how AOC did.
I can tell you this right now I can predict we will be voting for a centrist democrat but I rather eat that then have another 4 years of the right wing mess that is our president.