They will find that the primary system, as it is set up, will work against them. If Hillary gets in trouble, Bernie will sweep the primaries before Bloomberg manages to get organized and get his name on the ballot.
Except for one thing...
Out of 2,382 delegates to the Democrat convention, over 1/3 (nearly 800) are so-called "super-delegates" -- which are not allocated by the primary process.
The party bosses will still call the shots...
Election rules don't matter to them. They'll do whatever they want to do. See Lautenberg, Frank.
Bernie Sanders has an incredibly motivated and desperate base. After tying in Iowa, they are working over time to win every caucus.