I have felt for a long time that the DNC will do everything they can to prevent having Sanders as their nominee but in the end I don't think it really matters which one of them emerges as the nominee because Trump will defeat any of them, I think, in exactly the same way as 2016.
Imagine the internal rifts that will be created if they do, in fact, appear to have screwed Bernie again though... this will perhaps create an internal war to expose how corrupt the nomination process is.
I share your opinion IF anyone else than Sanders becomes the Democratic nominee; Trump will run circles around them all the time. However, Bernie is the real deal. He's the one candidate with a populist message, just like Trump, only without the lying and the cheating. It'll be hard, but Bernie can win.
That's one thing I appreciate about Bernie as well even though I disagree with his politics. He IS the real deal and except for a few moments like when he immediately supported Hilldog, I think that he is speaking what he truly believes even if it is unpopular and it is very refreshing to see truth in politics instead of speeches that mean nothing and were written by a team of writers.
Unfortunately, just like Ron Paul, Bernie is not part of the political machine and I didn't think he would ever be allowed to be the nominee. It's a pity that the fix is in so much but I suppose that is the nature of politics, probably globally.