Superdelegates will switch if the candidates have the actual votes. Hilary had the bulk of superdelegates in 2008 too early on, but they switched to Obama once he started winning more contests. Bernie never got there, he never had the votes that Obama had or even close.
Bernie ran a good campaign, but I think some people just need to understand it wasn't good enough. He needed to win a big state like California, which is he lost soundly to Clinton.
Hilary is tough to beat, she has a lot of Democratic support and the Clinton name is beloved by many in the Democratic party, she is by far the toughest opponent Obama had going head to head (he beat both McCain and Romney far more easily and would trounce Trump if he was running in this election).
States run polling stations by the way, not political parties.
If you want to win your party nomination there's a simple way to do it -- WIN more contests than your opponent, Sanders did not do that.
Of course Clinton is going to have some favoritism in the DNC, she has been a big part of the DNC for 30-40+ years and the wife of a 2 term Democratic president. Obama didn't make excuses, he went out an beat Clinton in the key contests and won the nomination and he dealt with the same disadvantages Sanders had.
