There is absolutely no reason for Sanders to sacrifice his goals to Democratic party unity, he isn’t a Democrat. I think he knew coming into this campaign that he would either become president or he would retire.
Leading Democrats are growing increasingly vocal in their concerns about the White House hopeful’s continued candidacy, and whether he and his legions of enthusiastic supporters ultimately will unite behind Hillary Clinton in a general election against Donald Trump. For his part, Sanders has sharpened his critique of the party. He says it would be “sad and tragic” if Democrats don’t stop relying on big money, and he is assailing Clinton for her dependence on wealthy donors.
So, what do they have to negotiate with? This is the only way they are going to have their peaceful convention, by coming to terms with Sanders’ terms. That’s the only way they are going to be able to keep the Sanders supporters in their corner is through negotiation. Loyalty will not come into play here.