Bernie was originally in the race as fake opposition: there to create the false impression of a primary election rather than a coronation for Hillary. He was the only Democrat other than Hillary to get any decent media coverage because he was considered unelectable. For a while, Bernie played the part of fake opposition well, i.e. saying "we're all tired of hearing about your damn emails."
When Bernie realized that in spite of this he was winning in major states, he went from fake opposition to authentic opposition. But the joke's on him. In the end, even if he manages to muscle ahead of Hillary in pledged delegates after solid primary wins, the superdelegates will see to it that Hillary gets the nomination. It's not so different from what the RNC is trying to do to Trump and his supporters.
There is one big difference. The DNC is trying to ensure Hillary gets elected. The RNC is trying to ensure that Trump doesn’t get elected.