Left wing Democrats (i.e., the most liberal of the liberal base), the folks who'd support Sanders are simply the loudest and most passionate in the party; they're still a clear minority, far outnumbered by the combined forces of moderate and conservative Democrats.
He'd get creamed.
Actually, I remember seeing a poll, that the breakdown was something like 65-15-10. There's actually more opposition to Hillary from the RIGHT than from the left.
65 Hillary
15 want someone more conservative than Hillary
10 want someone more liberal than Hillary
So even ignoring Hillary's supermajority, there's no way a single candidate would be able to unite the anti-Hillary vote. One side wants Joe Manchin, the other wants Bernie Sanders.
Poll
