Editorial: The Democrat field was so weak, Bloomberg brought his mega-bucks into the game. It was not to win. He really wants to take Trump down, and he does not see a candidate that can beat the incumbent. Bernie might have a shot, but establishment democrats abhor the idea of a socialist leading the ticket. He intends to force a brokered convention where superdelegates can force their choice, even if it is somebody who has not gathered as many delegates or a savior that has not even been campaigning. It will be chaotic, but it is the only hope they have. They cannot accept Bernie or Warren, so his plan is to pull enough delegates so nobody goes into the convention as the clear first ballot choice.
Bottom line: Bernie gets screwed again, the party splinters, and Trump sails to victory.
Bernie isn't getting screwed; he's winning, by his standards, because he's getting rich, and some people are listening to his bat-shit crazy ideas as if they aren't bat-shit crazy.
Obamas To Swoop In, Avoid Brokered Convention.
In general, a successful President with a good economy will be reelected. The truth is that Americans that are pretty happy with their lives don't want that wrenched away by an unnecessary change at the top.