I do find it weird how certain groups get into vote policing. It's not your vote, just because you want something or believe something doesn't mean others do, what democracy means isn't getting what you want, it's that everyone can cast a vote. It's also especially annoying when white people express emotion on behalf of minorities. Don't do that, if it's not about you, don't make it about you.
At the same time I don't for a second believe that Biden represents anyone's best shot. Best go full bore a pick a true progressive, the swing voters will fall in line, they just want to be on the cool team (and Trump is pretty uncool at this point). They want action, they want spectacle, and they definitely don't scrutinize policy. The worst you can do is run with a boring candidate.