You've got to be getting dizzy trying to spin this. By your own admission, Bernie is a Democratic SOCIALIST, NOT a Democrat. He runs as an Independent, NOT as a Democrat. (If he's so proud of his beliefs, why doesn't he run as a Social Democrat instead of and Independent?) He caucuses with the Democrats, because they share so many Socialist views, but that still doesn't make him a Democrat. The question still remains - Why are the Democrats allowing an Independent to be included in their debates? One would think they would be more interested in nominating a REAL Democrat.
The only rational reason, that comes to mind, is that the Democratic Party made this concession to Bernie to keep him from running as an Independent, for fear that he would "Nader" them in the '16 election.
Now. try to get off your high horse, quit being so condescending and answer the question, which was neither idiotic or crazy. Saul Alinsky would be proud, that you read his book and like to practice his methods.