Why was the Democratic establishment so united behind Clinton in the beginning?

[super6646]

I really doubt that. The democrats thought she was going to win, why else would they nominate her and put so much support behind her. Why run a great campaign if you are a "sacrifical lamb"?

Back to the OP, I really don't think they wanted another outsider. Obama's win was an upset for the democrats, and he ultimately ended up being a disaster down-ballet. In his 8 years, they lost the senate, the house, the majority of governorships, and many state state legislatures. While he could do great during election years, he simply couldn't appeal to voters during midterms and at the state level, which really ruined the democrats ability to pass legislation.

So my hypothesis is that the reason they didn't support Sanders (or any other outsider) is because they thought Hillary could stop the bleeding. Of course, thats rediculous. Hillary was not the same as Hillary 2008 - no longer a centrist, and no longer for the working class. She tried not to bring up the issues, and deflect with "trump is bad". I guarentee you, the time Hillary would have in office would bring about a disaster in terms of their performance down-ballet, and I think there could've a good chance the party would no longer be seen as a contendor in any part of government except for the white house if Hillary lasted 8 years as president.