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

[Mister Mets]

There were a few factors.

- She had support from multiple segments. She was the clear favorite of her husband's affiliates. She served in the Obama administration. Middle-aged feminists had loved her since the early 90s and saw her as the first female President. She had sewn up New York's fundraisers, and gotten to know the others for decades.

- Democrats have started focusing on identity politics, and they really wanted to nominate a woman after the last big milestone (Obama.) She was the most obvious choice.

- Because no one else had such wide support, it would discourage serious opponents. Biden might fight her for the Obama supporters, but there would still be the Clinton folks/ New York fundrasiers. Gilibrand might fight her for the feminists and New York fundraisers, but she'd be some of their second choice, and there would be still be the White House connections from two administrations.

- They bought into the "it's her turn" narrative, and wanted to reward her for supporting Obama after a tough primary. It's tough for Democrats to argue the point of rewarding the next in line when women and minorities have risen to that position.

- These advantages led to a feedback loop. She was so well-positioned, so she had a lot of support, which made her better-positioned which gave her more support.

- Because she was seen as a frontrunner, people wanted to be on her side, and didn't want to be seen as going against her. Part of that is a desire to back the winner, although the Clintons also have a reputation for pettiness.