I have my preferences, but I'm trying to avoid getting emotionally enmeshed in the primary. This is difficult, since I've worked in politics and everyone wants my opinion on the primary. ALSO DIFFICULT BECAUSE I HAVE OPINIONS.
Whoever wins, I will support them. Even if it's one of the 2-3 people I would be kind of annoyed about. I wasn't in love with Clinton either, but I canvassed and phone banked because the other option was Trump.
I will say, I think it's a mistake to overlook Biden's history with Anita Hill. Maybe a lot of people being polled aren't even aware of it, but it would become a huge issue in the general, and give Republicans cover to point back against Trump accusations. One of Trump's strongest defenses was pointing his finger at Bill Clinton, making people disillusioned with both sides.
The Democratic Party will do much better in focusing their energies on boosting turnout among apathetic left-leaning voters than trying to sway white, working class men. Nothing will placate that group (as a whole, of course there are a ton of individual of white working class men who reliably vote Democratic).
Is this based on any research? It is incredibly difficult to get a non-voter to turn out. Democrats are always working to increase turnout, but sometimes that's not enough. You have to overcome voter apathy
and structural barriers to voting. If there is a large base of potentially persuadable, reliable voters, vs a base of low-propensity likely supporters, it all depends on the size of each group. In some swing states, there simply aren't a lot of non-voting supporters to target, and you need to run persuasion campaigns.
There's a substantial segment of Obama voters who then voted for Trump in some swing states. Why should Democrats ignore them?