We lost months ago, when the DNC rammed Clinton through over Sanders.
EDIT: You simply cannot say it was the peoples' fault for not voting for her (pick someone electable next time); she had her choice between picking between what was best for her and what was best for the country, and we all lost because she was selfish.
I hope Sanders supporters step up and begin purging DNC incumbents in down ballot races. It is the only way forward.
It would have been about left vs. right if Sanders had been the nominee, since neither of them was a status quo candidate. Sanders has ardent supporters, but not very many of them.
Both Wisconsin and Michigan went for Sanders in the primary, both very unexpectedly, and then went heavily towards Trump in the general. Sanders would've easily won.