The centrists have backed him as their candidate (and the DNC / media have pushed for him, resulting in ridiculous articles like this one.)

Biden's peak was 41.4% on May 9th -- his "announcement boost" and he has been in steady decline since then.

He's down 14.2 points in under 60 days.

72.8% of Democrats remain -- mostly declared for Progressive candidates.

He's the front-runner because the rest of the party vote is split; He's just waiting for his "Please clap" moment.