Good answer. And I thought of mentioning Sanders, but he has been a long time politician himself, so either he's more part of the status quo than even he knows, OR this is an indictment of the overwhelming monstrosity of the system and how it has become too large for a single person to change.
He is a long term politician, but one that has somewhat evolved over the years. In a way marching further left the more he is up on the hill.
What this seems to come down to from my chair is the 2016 campaign is showing us something about the Democratic Party establishment. Perhaps in a way that the 2008 campaign sidestepped because of Bush 43, economic disaster, the status of ongoing conflicts and wars, etc.
I assumed back when Hillary announced that her path to the nod, and a general election win, boiled down to as little press time as possible to protect her as to then win on name, history, being a woman, and her time in Obama's administration.
Then Sanders showed up and for the most part has forced Hillary back into the networks for coverage, and also forced Hillary to brand herself as a liberal offering her own policies and directions I think the original campaign plan would have liked to avoid.
Sanders infinitely represents more counter to "status quo" than Hillary, which is interesting to consider when thinking about Obama vs. Hillary back in 2008. If anything, Obama represented something of a departure for Democrats far more than Hillary ever could either then or now. That lack of experience was something Hillary mentioned of Obama back in 2008, the "status quo" with Democratic establishment was tested.
Now, not so much. The goal is to do something not done in a very long time, back to back Democratic Presidents. We can only assume that establishment is doing all it can to ensure it happens, and they might get help from Republicans if they are to give Trump the nod. Sanders will not get the chance as a challenge to "status quo" in similar way Obama did, simply because of what is at stake in a general election this time around. That is more or less confirmed by the direction Congress has gone from 111th being all Democratic controlled in transition to the 114th being all Republican controlled. Odds are the 115th will be Republican as well assuming a few things, but the last thing Democrats need is a Republican President in 2016 as it would force them to do then what they did during the 109th Congress. Complain about Bush 43 and Republicans, until they won the 110th Congress.
Establishment for Democrats seems to be stepping in, perhaps as a means to ensure a historical moment. Going from a black President to a female President, we cannot rule that out even if Sanders is a better liberal (over Hillary, any other 2016 Democratic hopeful, Obama, Pelosi, Reed, and dozens of others up on the hill these days.)