The chair of the DNC was forced to resign because the Democrats were caught conspiring against Sanders theguardian.com/us-news/2016/jul/24/debbie-wasserman-schultz-resigns-dnc-chair-emails-sanders “She has been forced to step aside after a leak of internal DNC emails showed officials actively favouring Hillary Clinton during the presidential primary and plotting against Clinton’s rival, Bernie Sanders.”
Sanders supporters sued the DNC and their defense was picking the Democratic nominee was free speech and that they had every right to, “go into back rooms like they used to and smoke cigars and pick the candidate that way.”
Despite article IV section 5 of the DNC charter stating, “The chairperson is required to exercise impartiality and evenhandedness in the preparation and conduct of the presidential nomination process, specifically between the presidential candidates and campaigns. It is important that all parties involved adhere to these guidelines to ensure a fair and just process for all candidates.”