Hey, we're about the same age -- not Millenials, and I share your sentiments. However, the D party can't be trusted to go left. Indeed, we now have a one party system, a political system that serves corporate America. Of course it's a lousy idea, but that's what they've done.
It's up to us to prove that money (and advertising) won't sway us into voting against our own best interests anymore.
Sanders, I do not blame him. He has been consistently supportive of the working class his whole political career.
I do blame the DNC for their short-sightedness -- no visionaries there; only concerned with the bottom line for this quarter is the way things will go. They are not even good capitalists! They are intent on killing the host in their greed and will continue, like locusts to destroy the world's economy because they are cushioned from the effects of both a Trump or Clinton presidency through the entitlement of money. That the vote was rigged was evident from the first primaries for those who were paying attention. That the DNC showed favoritism at the git-go, allowing Sanders to run only if he would concede to Clinton when she was nominated, was a first clue as to how they were going to play the election. It's a game to them.
It's terrible that the voting population in its' entirety couldn't figure out that Sanders was the best choice, because for the 99% there really was no better candidate. Though we'll never really know what the vote was since Clinton statistically did so much better in every electoral precinct that had no means to verify the vote. Statistically, it was too anomalous to be coincidental.
Disgusted with the idea that the Dem party support a rigged election (and anyone who votes for Clinton, btw), I turned in my Democratic voter registration as soon as my primary was over and registered as Green. So, I will vote for Jill Stein. As much as I cringe at a Trump presidency, he does not have the support of corporate America and will be impotent in many regards. Pence isn't much better, but we'll probably do better in many ways than with a Clinton presidency. With Trump, the effects will probably be more local, with Clinton, the effects will be felt worldwide. Don't even ask me about Kaine.
The Dem party is just now comprised of Republicans who've moved into the party, leaving their own party to the far-right fringe. They don't care which party they own, so long as it does their bidding and can fool enough loyalists to continue to fund and support them.