Please.
Bernie's biggest weakness and one that's been his continual undoing is that he's a politician who thinks he's too good for politics. The "political machine"--that is, the web of personal and political relationships that underlay American politics--is a fact. The DNC--the structure of the Democratic Party--is a fact. Bernie finds these things distasteful and rages against them; his distaste, however, doesn't mean they cease to exist as realities to be dealt with rather than ignored.. His decision to pretend otherwise, in effect to disregard reality, speaks poorly of him, as a politician and a candidate. It was straight hubris, and hubris is never an attractive quality.