@engineer,
Although I generally give credence to most of your opinions because they seem thought-out and measured, I don't think you're correct on this issue.
The establishment Democrats have moved FAR right since Clinton. I know you guys say HRC has voted close to Bernie, but people who watch the facts as they happen know HRC (and Obama) have expressed a LOT of conservative rhetoric and put energy behind corporate and conservative policies.
Bernie is in a different universe from HRC.
If the Progressives are willing to split from the establishment Dems - and they lose to the GOP, I'm betting the establishments will either shift left so this ******* country HAS a left - or they will just start voting what they really are - Republicans.
This country needs a legit left.
What I am hearing, seeing, and FEELING is that we will carve out a party with or without the establishment conservative so-called Democrat party.
They will never win again without the Progressives.