There is zero fair play at that level of politics, and if you have been coddled on your path to that chair in any way, including expectations of the orderly and fair appraisal of the absolute merits of your platform, you are unprepared.
I'm saying that Clinton, with all her party machinations, is proving that she understands and has controls over real levers of power, which in turn, suggests she is capable of operating at the level required for that position.
Sanders came in expecting a fair fight, and that's completely unrealistic, naive, little league politics. If you can't survive your party's nominating process, whatever that is, you are a light snack for the players at that level.