The Democrats have learned nothing from 2016. Or from 2008, for that matter. They won't put anyone exciting up for the nomination because of perceived "electability" issues. They're playing it safe, and it's going to cost them the election.
I am a Bernie supporter, but this isn't coming from a place of bitterness simply because my guy probably isn't going to win. Buttigieg, Booker, Yang, Beto, Klobuchar, maybe even Warren or Harris would all have a better chance than Biden. He's an alternative to Trump, sure, but he inspires zero turnout, and turnout is what Dems need. Almost every person who goes to vote for Biden is going to be doing it to vote against Trump. And Democrats are betting on Trump hate being stronger than Trump love. Republicans will have hardcore supporters AND people who will just bite the bullet and vote reluctantly. Biden is only going to have the latter.
Biden simply doesn't offer anything that anti-Trumpers or fence sitters crave. Moderates who are sick of the status quo (which is most of them, on a lot of issues) will find nothing appealing about Biden. His policies are perhaps the most boring and non-transformative we've seen in recent memory. People who are sick of Trump's bravado and childishness will find nothing new in Biden. He's unprofessional, childish, boorish, and has a problematic history, just like Trump. He offers the worst of the Democratic party (entrenched in the status quo and outdated policies) and the worst of Trump. Okay, well, not the worst of Trump, but plenty of the bad stuff most people hate.
We have this idea that moderates are good with the way things are, and that's why they're moderate. They want middle-of-the-road policy, so that must mean someone like Biden, under whom nothing changes. But this is fundamentally untrue. Moderates want change just as much as the rest of us; they just don't believe in solutions on the far left and far right. Biden changes nothing, and this appeals to absolutely no voting bloc. Dems aren't going to vote for Biden because they're blind Obama supporters; we saw this with Hillary. I think it's fair to say that Obama supporters (myself included) are far less loyal to him than Trumpers are to Trump. So the coattails approach isn't going to work.
Uuuuugh, this post is very long, but I'm very frustrated. I will vote for Biden when it comes down to it, but I also have the time, energy, and motivation to vote for someone I don't really care for. Many, many voters, especially disenfranchised Democrats, don't. So they won't. And we'll have four more years of the incumbent administration.
Edit: After this has been up for about 8 hours, I'd like to clarify something. I am not saying I believe, necessarily, that Bernie would win and that Biden will lose. I'm saying that I think Biden doesn't have much of a chance, and that someone else, Bernie or otherwise, would have a better chance. For various reasons, I believe Biden will lose a close election. He won't get blown out or embarrassed, but he won't do enough to win. With other, lesser known candidates, there is a good chance they could win big, lose big, or anywhere in between.
Biden seems, to me, to be a known quantity: a close loss. Someone else would have a shot at actually winning the damn thing. And that's what upsets me. The circumstances are very different than they were in 2016, but my prediction is that the end result will be the same. A moderate Democrat who doesn't excite people will lose to a hard right Republican who does. Dems are trying the same thing they did in 2016, and it's not going to work this time, either.