Does anyone understand the democratic primary?

Very simple, so the voters dont matter

As is common on RallyPoint, the responses to your question contain an awful lot of opinion (most of which is partisan-fueled vitriol against Democrats) and almost no real answers.

BLUF: Superdelegates exist because control of the political party matters to the Democrats (one should ask if the RNC won't enact similar rules following this year's primary processes).
Here's some background reading:
http://www.dailykos.com/story/2008/2/15/457181/-
http://www.hks.harvard.edu/news-events/news/news-archive/history-of-superdelegates

Sadly, even though finding the answers to questions like yours takes about two seconds of googling, most RallyPointers would rather spout unsubstantiated opinion than actually engage in meaningful discussion backed by data and research.

Precisely why the Republican Party probably wishes they had them now. Populist movements can be flash in the pan and take ugly turns. Super delegates serve the Same purpose as the Senate. They aren't there to thwart the will of the people. They are there to make sure we the people don't wake up in the morning after a Tequila bender and say "What did we do?".

Mr. Trump is controversial inside and outside of the Republican Party. Win or lose, Mr. Trump will be used as a stick to beat up on Republican Candidates for a very long time. In some cases Republican candidates that found him repugnant, will be labeled by association. The only way out for the Republicans is for Mr. Trump to win the elections and become a very successful president. Otherwise he's just unexploded ordnance in the bed of your pickup truck.