They are just following the lead of Sanders who has turned into a narcissistic antidemocratic asshole. When the candidate refuses to accept the will of the voters one can't expect the followers to accept it either.

the Vermont senator insisted that the delegate count is fluid. And he expressed confidence that he could persuade some “super delegates”— the party leaders who are not locked into voting for a particular candidate — to peel away from Clinton in the “six long weeks” before Democrats gather in Philadelphia.

“Now, I have heard reports that Secretary Clinton has said it’s all going to be over on Tuesday night. I have heard reports that the media, after the New Jersey results come in, are going to declare that it is all over. That simply is not accurate,” Sanders said at a news conference here.

Sanders then added, with emphasis, that the “Democratic National Convention will be a contested convention.”

Barrett Pitner, writing for the Daily Beast, wrote a very interesting article about his conversation as a black Bernie supporter having a conversation with some white Bernie supporters:  

http://www.thedailybeast.com/articles/2016/06/05/the-white-entitlement-o...

Here is a bit of an excerpt that started with him over-hearing a conversation:

" Killery Clinton is stealing the nomination and the system is rigged against Bernie Sanders," said the two young white guys standing behind me in line. They rambled incessantly about how she was cheating and could not be trusted. Superdelegates were their greatest frustration. Unelected delegates who could "decide" the nomination proved that the process was a sham that was intentionally set up to prevent Sanders from winning.

At first I tried to ignore the conversation and thought they were Trump supporters ("Killery" is usually a right-wing thing). But once it became clear that these guys were Sanders supporters, I had to jump in. For years, these guys had been "my people." I have been a fan of Sanders long before his presidential run and have made many friends due to our mutual admiration of his policies. Surely, I'd be able to have a civil, rational conversation with these guys, right? When, I chimed in it was evident that we were speaking different languages.

We agreed on most of the substantive policy issues, and I told them how I even interned for Sanders about a decade ago. We should have been able to see eye to eye, but we could not. The main source of their frustration was merely the fact that they had lost. The fact that she is ahead in the popular vote, has won more primaries and caucuses, and has earned more delegates was to them a minor nuisance. They had their absurd talking points and were unwilling to deviate into reality. The more I reflected on them, the more I realized the key point: They felt entitled to win, and a defeat meant that someone must have cheated or that their opinions did not matter, which of course couldn't be true. They preferred to suspend reality and fabricate injustices rather than concede that Sanders has lost fair and square.

Essentially, we disagreed on what America supposedly promised or owed us. They felt success was promised to them. The entitlement to believe that you should always win allowed them to overlook how the system in many ways has always been unjustly rigged in their favor because they're white. I brought up race during our conversation and how I'm very aware of how a system can be rigged against you. These guys acknowledged my point, but it was obvious that this reality did not factor much into their thinking. They felt aggrieved and cheated, and that was all that mattered. They could not understand the perspectives of blacks, Latinos and other minorities in America who are regularly treated as threats to society before their voices can be heard. We are often silenced before we even have the chance to win. And as a result, we know that losing is a reality we will confront and that success can be a difficult and long process that may only show its face in the lives of our children or grandchildren who have more opportunities because we've spent a lifetime fighting for positive change.

These guys could not understand this struggle. They wanted immediate success and gratification, and they were not used to things not going their way. The issues and the lives of others had become irrelevant. All they wanted was for me to agree that they had been unjustly cheated, and that "Killary" and the DNC had rigged everything against them.

I could not agree, so I had to walk away. Sander's message has resonated mostly with a younger, predominantly white electorate like those two guys. Their message and frustrations have been heard loud and clear, but their electoral defeats have resulted in an intensified pack or tribalist mentality that unfortunately has similarities to the white tribalism that has guided Trump's campaign. Sanders and Trump are mining similar disaffections amongst the white electorate.

rmrd0000, are you familiar with Pitner?

rmrd0000 - for months you have been telling us the black community prefers Hillary Clinton.  Is the black community familiar with the breach between the Clintons and Peter Edelman and Marian Wright Edelman over their support for welfare reform?  Are the Edelmans well-regarded in the African-American community?  https://www.washingtonpost.com/politics/inside-hillary-clintons-long-ten...