ramble, take offence.
if you like conspiracy theories and US politics then lets imagine that the fear was a left winger would lose the democrats the popular vote and if the republicans had Jeb Bush as a middle of the road type the republicans would get in. so as a reaction it was agreed that Hillary should use her influences to lean it in her favour, as a result, she established a lead meaning she has way more than 50% of her party on side. the trouble was a right wing nut got the republic candidacy, and the Hillary camp rigging and deceptive political methods caused a backlash which ensured a close run thing. So Bernie was powered by Hillary Clinton's camp's activities that they thought at first was the best way to beat Bush, sounds sexy, or beat Cruz, and now is a lame duck to face trump? the conspiring to ensure democrats win has meant the democrats are losing the left which is swelling the greens and trump as a right winger is far more likely to win the presidential race.
So if Hillary played fair to win democrats rather than trying to warm up the general population ready for November then she'd not have made her Frankenstein(Sanders) and he's monstrous following(Bernie fans, soon to be greens?). She created her worst nightmare, someone who wasn't trying to be all things at once, just as in previous cases where a candidate was about being middle of the road, progressive, and anything that gets me ahead.
Lets just call this a fool's opinion, I'm sure better authorities know better on this issue than I.