I see your problem, you think things have worked well in the past. For the Purity Brigade, clearly since we don’t have a purely progressive government already in place, this proves this not to be true.
Personally, I’ve been telling everybody I speak to about this to put your own personal goals on the shelf for this round - we absolutely need to scare the living bejeesus out of the Replublican party if we’re to get any changes, so please - vote and vote strategically. For Californians, this may mean voting for your favorite candidate in the primary (assuming this doesn’t “pull a Trump” and spread the Democratic vote across 13 candidates, leaving two Republicans at the top of the ticket), but once we get to the Big Show, please don’t do anything but vote them out.
If we don’t scare them enough, they’ll continue to sit on the fence and watch Cadet Bonespur screw things up. Those already in it up to their eyeballs should be considered lost until the indictments are all distributed, but assuming not every single one of them in corrupted, the rest should then be able to start the long road back…